Made allocation.{h,cc} independent of V8, allowing utils.h to allocate
vectors and collectors.

Review URL: http://codereview.chromium.org/5005001

git-svn-id: http://v8.googlecode.com/svn/branches/bleeding_edge@5826 ce2b1a6d-e550-0410-aec6-3dcde31c8c00