Fixed compiler warnings (detected by VC++):
- Removed not used variables
- Added casts
- Fixed wrong assignments to bool
- Fixed wrong calls with bool arguments
- Added missing argument to store(longlong), which caused wrong store method to be called.
* Cleanup SP Cache code, now SP Cache only deletes sp_head objects in
sp_cache_flush_obsolete() invalidates all pointers to routines in the cache.
* Use new SP Cache use contract in the code.
There is no test case because it doesn't seem to be possible to cause thread races to end
the same way they end in heavy-load test. This patch removes the crash in heavy test.
Phase 2: Make SPs belong to a DB, and use qualified names.
As a side effect, using USE in an SP is no longer allowed.
(It just doesn't work otherwise.)
New sp_cache C API. When an SP is dropped, old caches (in other threads)
become invalid and are cleared.
Also, the caches in THD are only created on demand.
