Tcl package Thread source code

I was wondering that if tcl application properly exits (calling all exit-handlers, etc.), then all still bound persistent storages are flushed (together with arrays, by implicit delete of all arrays in SvFinalize).

IMHO this is a bug, because I believe the name "persistent storage" means persistent.
But ATM only if "unbound" called before exit, it does not occur.

Fixed within [c00a271dae] now.

Additionally this resolves a memory leak by "tsv::array unbound" (especially annoying if bound/unbound switching often).

See check-in [c00a271dae] for more info.

BTW. I've created still one branch with possibility to compile with lmdb handler for windows, see [31d323157d].

Any objections?
If not, I'll merge in the comming week.