WIXBUG:4474

Add missing headers; relocate headers to sdk\inc; add missing file and
correct typo to point to deputil directory.
Support VS Express for native SDK packages

Install native SDK packages when VS Express SKUs (VC++ Express v10 or
Windows Desktop Express v11/v12), in addition to Professional and later.
Undo inc directory move
Several small fixes for self updates/feed processing.
* jchoover: Switch WixBA over to using engine updates.
Missed interpreting user result to hr during DetectUpdate.
Merge branch 'updates-core' into updates-wixba
Style tweaks
Merge pull request #117 from barnson/nativesdk.express

Conflicts:
	History.md
Fix whitespace
Tweaked after code review.
Merge branch 'updates-wixba' of git://github.com/jchoover/wix3 into develop
Style cleanup and logging
Merge branch 'develop' of https://github.com/wixtoolset/wix3 into develop

Conflicts:
	History.md
Fix history
Merge branch 'develop' of https://github.com/wixtoolset/wix3 into develop

Conflicts:
	History.md
Merge pull request #115 from barnson/bug4474

Conflicts:
	History.md
WixBuild: Version 3.9.720.0
Merge pull request #122 from wixbuild/develop

WixBuild: Version 3.9.720.0
WixBuild: Version 3.9.721.0