app: remove binary file descriptor workaround for windows

Signed-off-by: David Aguilar <davvid@gmail.com>
guicmds: mark strings for l10n

Signed-off-by: David Aguilar <davvid@gmail.com>
gitcmds: add diff() function

Return the filenames that differ given the provided arguments.
This is an interface on top of "git diff", which is plumbing,
but we call it with "--name-only -z" which makes the output
predicatable.  This lets us have the ability to diff against index,
worktree, and arbitrary commits using a single interface.

Signed-off-by: David Aguilar <davvid@gmail.com>
difftool: add a text field for editing diff arguments

This makes the Diff->Expression action much more flexible as we can now
modify what we're diffing on-the-fly.

Signed-off-by: David Aguilar <davvid@gmail.com>
main.view: remove "Diff->Revision" menu action

This action is redundant now since the general "Diff->Expression" dialog
lets you do everything that was possible before (and more).

Signed-off-by: David Aguilar <davvid@gmail.com>
cola: update copyright for 2013

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

One day cola will be ported to python3.  One day.

Signed-off-by: David Aguilar <davvid@gmail.com>
cola: add `git cola diff` sub-command

Signed-off-by: David Aguilar <davvid@gmail.com>
git-cola v1.8.2

Signed-off-by: David Aguilar <davvid@gmail.com>