Get information from outside of the project

[pythonissam]

Under the current implementation, .git must be in the project. I suggest that we give git command the visibility of other directories in addition to the current directory.

[jneira]

Oh, afaik there is a mechanism to tell the lib where is the .git directory: putting a file named .git with the contents:

 gitdir: /path/to/custom/.git

see

gitrev/src/Development/GitRev.hs

Lines 112 to 118 in 450a7ab

	splitAt 8 `fmap` readFile dotGit >>= \case
	("gitdir: ", relDir) -> do
	isRelDir <- doesDirectoryExist relDir
	if isRelDir
	then return relDir
	else oops
	_ -> oops