Malformatted options

[StyXman]

I'm using git.Git a lot for calling low level git commands; for instance, git commit-tree. In particular, I'm trying to use the -m option, but Git.transform_kwargs() converts m='foo' into -mfoo, which git rejects:

git commit-tree -mfoo e53dc311b7e3ac674f3a6548a22113307a6af3ef -> 128; stdout: '<OUTPUT_STREAM>'; stderr: 'fatal: Not a valid object name -mfoo'

I'm not sure if the current formatting is like so for any particular reason, and I found about the split_single_char_options argument, but there seems to be no way to control that via the API.

[Byron]

I totally agree and am not sure myself why it is implemented in that particular way. Changing the default might be a suitable fix (e.g. setting split_single_char_options could be turned on by default).

Would you like to submit a PR for this ? Chances are everything will just work fine after that, while fixing the issue.

[StyXman]

Well, the unit tests don't pass in my machine (tests py2.7 [FAILED (errors=10, failures=3)] and 3.4 [FAILED (errors=10, failures=2)]), but the fix is simple enough and travis gives OK. Maybe you can try it on your side? See #341.