Fix bug that causes the build to break when profillingsupport=off (issue 738).

Added expose-externalize-string flag for testing extensions.

Resolve linker issues with using V8 as a DLL causing a number of problems with unresolved symbols.

Fix build failure for cctests when ENABLE_DEBUGGER_SUPPORT is not defined.

Performance improvements on all platforms.


git-svn-id: http://v8.googlecode.com/svn/trunk@4924 ce2b1a6d-e550-0410-aec6-3dcde31c8c00