Git Support ready-ness

[David Nolden]

About the Git menu entries again:
- I find the "Update" menu entry confusing. Seems like it does the
same as "Pull", but there is also a "Pull" entry, so the "Update"
entry should disappear.
- Also the "Revision History" entry does nothing at all here, and
since there's "History", "Revision History" should also be removed.
- Also the "Compare to Base" and "Compare to Head" entries are quite
annoying, as I simply don't know what the difference between them is,
and user also won't get it. "Compare to Head" should IMO go away, and
maybe "Compare to Base" should be changed to "Local Changes..." or
something like that. However since those changes can also be inspected
when pushing "Commit...", maybe that entry could also go.
- I think "Branch Manager" should be renamed to "Branches..."
- Since "Push..." and "Pull..." always operate on the whole
repository, I think those should only be shown in the context-menu of
the whole repository. The same is probably true for the stash- and
branch-entries
- "Push..." and "Pull..." are misleading, as their name suggests that
there will be a menu (due to the "..."), but at least for "Pull" there
is none.

Greetings, David