[Windows] Don't use pdevenv when building with VS2010.
https://bugs.webkit.org/show_bug.cgi?id=116338.

Reviewed by Adam Roben.

* Scripts/webkitdirs.pm:
(setupCygwinEnv): Check if we are using VS2005, and only use
the 'pdevenv' hack if we are. Otherwise, just build with
our standard project since it uses VS2010+'s native
parallel building features.


git-svn-id: http://svn.webkit.org/repository/webkit/trunk@150281 268f45cc-cd09-0410-ab3c-d52691b4dbfc