[Win] Extend auto-version and version-stamp for RC_ProjectBuildVersion

[Win] Extend auto-version and version-stamp for RC_ProjectBuildVersion
https://bugs.webkit.org/show_bug.cgi?id=135948
<rdar://problem/18022221>

Reviewed by David Kilzer.

Tools:

* Scripts/webkitperl/auto-version_unittest/autoVersionTests.pl: Add tests
for RC_ProjectBuildVersion.

WebKitLibraries:

* win/tools/scripts/auto-version.pl:
(splitVersion): Use RC_ProjectBuildVersion (or RC_PROJECTBUILDVERSION) if set
in the environment as the 'Build Version', unless the multi-tuple version
supplied by RC_ProjectSourceVersion already has a fourth component.
* win/tools/scripts/version-stamp.pl: Check for RC_ProjectBuildVersion and
use it in preference to RC_PROJECTBUILDVERSION.

git-svn-id: https://svn.webkit.org/repository/webkit/trunk@172604 268f45cc-cd09-0410-ab3c-d52691b4dbfc