version: be more robust when parsing Git versions

We cannot assume that the last element is the git version
string.  Apple's build of git, for example, adds an extra
"(Apple build XX)" to the end of the version string.

Make the parsing more robust by splitting like we did
before, but taking the 3rd element instead of assuming
that the last element is the one that contains the
version string.
qtcompat: move setStyleSheet() patching here

Signed-off-by: David Aguilar <davvid@gmail.com>
diffparse: remove unused variable

Signed-off-by: David Aguilar <davvid@gmail.com>
widgets.completion: scrub trailing whitespace

Signed-off-by: David Aguilar <davvid@gmail.com>
git: guard against "git version" saying "Git"

Signed-off-by: David Aguilar <davvid@gmail.com>
app: teach cola about modern homebrew

Modern versions of homebrew use a standard lib/python2.x/site-packages
directory structure.  Teach cola about it.

Signed-off-by: David Aguilar <davvid@gmail.com>
app: use sys.stderr.write() instead of print for better portability

Signed-off-by: David Aguilar <davvid@gmail.com>
i18n: teach the N_() function to handle translations

This is needed to fix #157.  We will begin marking all strings
for l10n  using N_('...').

Signed-off-by: David Aguilar <davvid@gmail.com>
app: simplify translation setup

We will be using i18n.N_() everywhere so we no longer need to monkey-
patch Qt's translate().

This is a pre-requisite for fixing #157.

Signed-off-by: David Aguilar <davvid@gmail.com>
i18n: mark strings for translation

Mark all strings for l10n using N_('...').
"python setup.py build_pot" now generates .po files
with these messages.

Closes #157

Reported-by: Sergey Leschina <mail@putnik.ws>
Signed-off-by: David Aguilar <davvid@gmail.com>