WIXBUG:4418

Release strings and remove dead code.
WIXFEAT:4378

Add WixBundleOriginalSourceFolder variable (WixBundleOriginalSource
minus file name).
Add WixBundleOriginalSourceFolder documentation
Merge pull request #35 from barnson/develop

WIXBUG:4418
Merge pull request #36 from barnson/wixfeat_4378

Conflicts:
	History.md
	src/burn/engine/cache.cpp
Merge pull request #37 from barnson/wixfeat_2742

Conflicts:
	History.md