First step in two-part process to rename directories to kallithea.
This first step is to change all references in the files where they refer
to the old directory name.

Imported some of the GPLv3'd changes from RhodeCode v2.2.5.

This imports changes between changesets 21af6c4eab3d and 6177597791c2 in
RhodeCode's original repository, including only changes to Python files and HTML.

RhodeCode clearly licensed its changes to these files under GPLv3
in their /LICENSE file, which states the following:
The Python code and integrated HTML are licensed under the GPLv3 license.

(See:
https://code.rhodecode.com/rhodecode/files/v2.2.5/LICENSE
or
http://web.archive.org/web/20140512193334/https://code.rhodecode.com/rhodecode/files/f3b123159901f15426d18e3dc395e8369f70ebe0/LICENSE
for an online copy of that LICENSE file)

Conservancy reviewed these changes and confirmed that they can be licensed as
a whole to the Kallithea project under GPLv3-only.

While some of the contents committed herein are clearly licensed
GPLv3-or-later, on the whole we must assume the are GPLv3-only, since the
statement above from RhodeCode indicates that they intend GPLv3-only as their
license, per GPLv3§14 and other relevant sections of GPLv3.

synced vcs with upstream

- moved subprocessio module to VCS
- many small changes to make embedded vcs as similar to to external lib
- use only absolute imports
- patch vcs config during load pylons env

compare and diff: remove unused "bundle" functionality

The 'bundle' parameter was never set, incoming_changesets was thus always
False, remote_compare was thus always False, and InMemoryBundleRepo and
bundlerepo was neverused.

Basic implementation of cherry picking changesets
for pull request, ref #575