Removed the current Xcode project file.

Fixed a few places where the C++ compiler supplied with Xcode produced warnings.
Review URL: http://codereview.chromium.org/7134016

git-svn-id: http://v8.googlecode.com/svn/branches/bleeding_edge@8228 ce2b1a6d-e550-0410-aec6-3dcde31c8c00