RevBy:    tba
Details:  - as on windows some git commands take much longer it happens fairly often, that git timeouts.
          - added a timeout value to the option to let the user choose maximum timeout value (minimum is 10 seconds, maximum 5 minutes)

The previous interface wasn't sufficient to properly support the Apply
button, since it didn't separate applying the changes from the cleanup
phase.

Designer settings pages still need some fixing.

Fixes Apply button causing problems for certain plugins, for example the
QuickOpen.