Adds -pthread and changes -I to -isystem in gtest's build instructions.


git-svn-id: http://googletest.googlecode.com/svn/trunk@638 861a406c-534a-0410-8894-cb66d6ee9925
Removes dangling references in make/cmake files.


git-svn-id: http://googletest.googlecode.com/svn/trunk@639 861a406c-534a-0410-8894-cb66d6ee9925