controllers: move controllers base class from lib/base to controllers

TG quickstart put it in lib/base.py , but it fits better on the controllers
layer as a base there.

The contributing docs were a bit ahead of time ... but with a typo.

lib: move webhelpers2 and friends to webutils

Gives less of the unfortunate use of helpers - especially in low level libs.

lib: fix bad references to utils3

A problem introduced in when rebasing 5e46f73f0d1c after renaming the temporary
utils3 name to webutils.

routing: separate url handling from routing - move it to webutils

This is a helper method relying on the thread local tg.request. We didn't have
a good place to put it. Now we do.

This (re)moves unfortunate dependencies to the routing module (which almost is
a controller).

permissions: drop hg.create.write_on_repogroup "Repository creation with group write access" setting

Simplify permissions system and get rid of some confusing tech debt.

Before, the global 'write_on_repogroup' setting controlled what write
permission on a repo group meant.

With this change, users can create repositories in a repo group if and only if
they have write access. Write access to a repo group will now mean the
permission to create repositories in it.

Write access to repo groups must be granted explicitly. There should not be any
other reason to grant write access than to allow users to create repos. There
is thus no upgrade concerns for this change.

An admin that doesn't want users to create repos in a repogroup should just not
give them write access.

These global settings might still exist in the database, but is ignored and no
longer used and do no harm.

auth: minor code improvements around global permission

Use immutable lists for constants ... just because we can.

Fix trailing dot in check for hg.create.write_on_repogroup.

Add missing (but so far unused) global permissions to PERM_WEIGHTS.

auth: drop confusing and layering-violating User.AuthUser property

Keep it simple and just explicitly create an AuthUser if "needed". That can
perhaps be simplified further later on.

controllers: rename __before__ to _before in preparation of TurboGears2

__before__ in Pylons is called _before in TurboGears2. We can prepare this
rename already in Pylons-based Kallithea, so that the real TG2 migration
commit just changes the BaseController.

Since TurboGears2 _before can pass extra arguments, we add *args and
**kwargs parameters as well.

tg: minimize future diff by some mocking and replacing some pylons imports with tg

No actual tg dependency yet, just a temporary hack faking tg as an alias for
pylons.

Based on work by Alessandro Molina.

Turbogears2 migration: replace pylons.url by kallithea.config.routing.url

In preparation for the migration to Turbogears2, introduce a
kallithea.config.routing.url to replace pylons.url. The implementation is
basically the same: wrap around routes.url().

This change involves:
- a number of import statement changes
- fixing some tests in test_libs.py; to avoid duplication, the different
implementations of fake_url were grouped in one place.

This change was first proposed by Alessandro Molina in his initial
port. Following changes were made afterwards:
- move UrlGenerator from kallithea.lib.utils to kallithea.config.routing
- add documentation to UrlGenerator
- kallithea/lib/auth.py used url_for instead of url, for no apparent reason
so this was changed.
- fix libs tests
- rebase onto Pylons-based Kallithea first

auth: remove HasPermissionAll and variants

First, find all calls to HasPermissionAll with only a single permission
given, and convert to equivalent calls to HasPermissionAny.

Next, observe that it's hard to envision situations requiring multiple
permissions (of the same scope: global/repo/repo group) to be satisfied.
Sufficiently hard that there are actually no such examples in the code.

Finally, considering that (should it ever be needed) HasPermissionAll
can be trivially built as a conjunction of HasPermissionAny calls (the
decorators, too) with only a small performance impact, simply remove
HasPermissionAll and related classes and functions.

cleanup: replace redirect with WebOb exceptions

All redirect does is to log "Generating 302 redirect" with logging the actual
location and raise a WebOb HTTPFound exception, and the logging is redundant,
as WebOb exceptions and their status codes are already logged.

Instead, just raise the exception directly, which is both explicit and simpler
(and finally, gets rid of "return redirect" which never really returns).

cleanup: remove unused imports

Found with pyflakes.

cleanup: consistently use 'except ... as ...:'

Use the Python 2.6+ syntax instead of the old confusing 'except ..., ...'
syntax.

controllers: consistently use formfill.render with force_defaults=False

The inconsistency could cause confusion for developers. It seems to me like
force_defaults=False should be the default ... and apparently it was that in
older versions of formfill.

It could perhaps make sense for us to have a wrapper that added the defualt
values once, instead of repeating it all over ;-)

Correct licensing information in individual files.

The top-level license file is now LICENSE.md.

Also, in various places where there should have been joint copyright holders
listed, a single copyright holder was listed. It does not appear easy to add
a link to a large list of copyright holders in these places, so it simply
refers to the fact that various authors hold copyright.

In future, if an easy method is discovered to link to a list from those
places, we should do so.

Finally, text is added to LICENSE.md to point to where the full list of
copyright holders is, and that Kallithea as a whole is GPLv3'd.

Second step in two-part process to rename directories.
This is the actual directory rename.