Merge pull request #185 from JustinJ/mock_retab_tests

modified method stubs to make test pass
Don't run :only when there's already < 2 editors open.
Add support for Vim's _ motion
Merge pull request #186 from JustinJ/underscore_motion

Add support for Vim's _ motion
Merge branch 'master' of https://github.com/vrapper/vrapper
Fix #187.  Add support for ':e!' to revert file.
Reduce code duplication.
Fix :g command.  I use a null range to be a special case, I don't want
it to be silently ignored.  Handle a null range in operations that had
been expecting range to not be null.
Fix line range operations.  My regex was bad.
Update unstable update site with some defect fixes.
Make paragraphs and sentences considered jumps
Fix #188.  Add support for copy and move line range operations.
Merge pull request #189 from justinj/paragraph_sentence_jumps

Make paragraphs and sentences considered jumps
Make line address parsing generic (utility method) so I can reuse it
when parsing destination address for copy/move lines.  This is a further
enhancement on #188.
Update unstable update site with a single new feature.
Fix #190.  Add ability to launch current file in gvim to perform any
operations Vrapper doesn't support.  When givm exits, Eclipse will
prompt to reload file.
Attempt to fix :vim command for opening files in gvim.
Update unstable update site with some minor tweaks.
Tell gvim to run in foreground mode so I know when it exits.