rebased on v1.9.3

Hello,
as v1.9.3.msysgit.0 is not tagged yet, I ran merging-rebase.sh --force v1.9.3, observed how the option is nicely propagated to shears.sh, replaced the rebase script by my one
https://github.com/kasal/msysgit-rebase/blob/f90309cd07c5868c9a5b157baa58bd3898b522ac/shears-script
and let the rebase proceed.

I have also verified that the new version has no test regression.

This PR is meant to be accepted by fast-forward, as the new master, and then used as v1.9.3.msysgit.0 to build a Git for Windows release.

This tree also includes the changes suggested in PR #183.

Stepan