This allows the git repository to be moved while git-annex is running in
it, with fewer problems.
On Windows, this avoids some of the problems with the absurdly small
MAX_PATH of 260 bytes. In particular, git-annex repositories should
work in deeper/longer directory structures than before. See
http://git-annex.branchable.com/bugs/__34__git-annex:_direct:_1_failed__34___on_Windows/
There are several possible ways this change could break git-annex:
1. If it changes its working directory while it's running, that would
be Bad News. Good news everyone! git-annex never does so. It would also
break thread safety, so all such things were stomped out long ago.
2. parentDir "." -> "" which is not a valid path. I had to fix one
instace of this, and I should probably wipe all calls to parentDir out
of the git-annex code base; it was never a good idea.
3. Things like relPathDirToFile require absolute input paths,
and code assumes that the git repo path is absolute and passes it to it
as-is. In the case of relPathDirToFile, I converted it to not make
this assumption.
Currently, the test suite has 16 failures.
cd865c3b8f