WIXBUG:4192

Guard against a null.
WIXBUG:4125

Clarify doc.
Merge branch 'develop' into bug.4125

Conflicts:
	History.md
WIXBUG:4134

Add <UI> overrides to WixUI localization for pt-BR.
WIXBUG:3701

Add a check for file size when verifying cab cache.
Merge pull request #40 from barnson/bug.4125

WIXBUG:4125
Merge pull request #41 from barnson/bug.4192

Conflicts:
	History.md
Merge pull request #42 from barnson/bug.4134

Conflicts:
	History.md
Merge pull request #43 from barnson/bug.3701

Conflicts:
	History.md
WixBuild: Version 3.9.526.0
Merge pull request #44 from wixbuild/develop

WixBuild: Version 3.9.526.0