Restore Git bash utilities to the PATH

[miketimofeev]

This is a quick fix for issue #282
In #211 C:\Program Files\Git\usr\bin was removed from the PATH caused to using Windows tar(C:\Windows\System32\tar.exe) instead of the tar comes along with Git. Windows doesn't have xz support by default, tries to use mingw xz utility and hangs.

Changes:

• Restore "C:\Program Files\Git\usr\bin" in the PATH, until MSYS2 is added(Add MSYS2 to Windows #30)

[maxim-lobanov]

Is any regression expected after these changes?
In scope of #211 , this line was removed so, probably, we can bring some issues back again

[miketimofeev]

Is any regression expected after these changes?
In scope of #211 , this line was removed so, probably, we can bring some issues back again

@maxim-lobanov complains were mostly about mingw64 directory in the PATH. And after #211 changes some of the tools are broken as explained in this comment
#211 (review)