DLL_THREAD_ATTACH/DLL_THREAD_DETACH notifications, call
DisableThreadLibraryCalls() in order to slightly improve performance
on thread creation/exiting.
debug channels definitions.
Made win32 the default type for spec files.
Ignore C compiler in winebuild so we can simply pass it $(DEFS).
Removed type win32 and debug_channels from spec files.
Fixed winebuild to always generate correct C identifiers (reported by
Vincent Béron).
Added -exe mode to generate a .spec.c for an exe without having to
provide a .spec.
Removed some no longer needed spec files.
Removed .dll extension in makefiles import specifications.