Fix exit code was not grabbed correctly.

Fixes GH-180.
Handle build cancellation in VS2012.

The size of this change belies the difficulty of getting this approach to work.

Fixes GH-178
Include xml files in installer.

Fix indentation mismatches.
Add Beta6 download links.
Fixed reverse exit code logic in VS2012 builds.
Build PathControl rather than downloading it.
Better dependencies for zip file.
Add download links for Beta6a

Fixes a couple of small VS2012 build annoyances, Beta6 reported every
build as failed.
Handle textual Depends.

Fixes GH-182
Integrated from main