Fixing 32-bit Windows build
Downgrading PortableGit version to 1.8.4 to avoid the git add behavior change in 1.8.5
Downgrading git to (depreceated) 1.8.3, because of the git add behavior change in git 1.8.4
Merge pull request #5367 from muratg/mgdev

Fixing 32-bit Windows build step: make win-extras