debugger_data_thread_coro_local: Improve.
debugger_data_thread_coro_local: Improve.

Improve local storage.
In SCHED_MULTITHREAD mode:
per-thread-per-coro
Use only one thread_local_storage key, implementation may limit
the number of keys, or not free them, and we allocate/free a lot of
coroutines.

In default monothread sched mode:
per-coro in default thread, per thread otherwise.

	* src/console-server.cc (debugger_data_thread_coro_local): Do that.

aldebaran/urbi,aldebaran/urbi,urbiforge/urbi,urbiforge/urbi,urbiforge/urbi,aldebaran/urbi,aldebaran/urbi,urbiforge/urbi,aldebaran/urbi,urbiforge/urbi,aldebaran/urbi,urbiforge/urbi,urbiforge/urbi,urbiforge/urbi,aldebaran/urbi,urbiforge/urbi,aldebaran/urbi