fixed memory leaks when creating lots of instances with a thread specific instance info object
Merge commit 'd4cccb53ab9db592f0ce19b647af7f5b13f79288'
Merge branch 'master' of github.com:jeremybarnes/jml
missing header for libstdc++ 4.7
Instanced TLS now recycles old indexes and no longer leaks memory.

Note that it also now guarantee that the destructor of TLS object is
invoked when the object dies or when the thread dies. A returned
pointer is also valid as long as the TLS object being pointed to is
also valid.

Conflicts:
	arch/thread_specific.h
Merge remote-tracking branch 'upstream/master'