Fix double escaping when Lawrencium is stored in a folder with spaces.
Kudos to Gareth Phillips for pointing out the solution :)
Fix a bug with `:Hgstatus` showing diff summaries in its own window.

This could happen when the user would commit from the status window, and
do a `:Hgstatusvdiffsum` right away. It wouldn't find the previous window
because it would be gone (the commit message window), so it would split the
status window itself, which is often too small.

Now Lawrencium tries to avoid picking the status window itself, and will just
find any other window instead.
Bumped version. I should release this stuff more often.
Added tag 0.4.0 for changeset e4e29a1da13c