Add require.paths support

Issues: https://github.com/n1k0/casperjs/issues/462 https://github.com/ariya/phantomjs/issues/11339
Getting ready for 1.9.2.

Issue #11452: https://github.com/ariya/phantomjs/issues/11452
Fix Clang compilation

Already merged in Qt: https://qt.gitorious.org/qt/qt/commit/b82b8bfa811adcf11cb8d07d662fd2b9642deebc

Issue #11611 https://github.com/ariya/phantomjs/pull/11611
REPL returns empty object on enumerating properties on a simple JavaScript type (Number, String, Logical).
We should not to do that.

Issue:
https://github.com/ariya/phantomjs/issues/11622