[win32 fixes] support using msys-based git
Submitted by Sam Thursfield
Git is really awkward on Win32. It is available packaged as MSYSgit, which ships with its own MSYS environment which is best kept seperate from the main one.
With this in mind I made a patch that allows changing the git command to the form: c:/tools/git/bin/sh.exe -c "/c/tools/bin/git %s"
This is ugly but it makes MSYS git work perfectly with jhbuild. Here is the patch. I will be surprised if anyone likes it :) But I am not sure of a better way to do this.