simplify/unify locking
import of initial unified lock
changes to m4/w32 removal, more housework
remove last call to RDUNLOCK, apache working but locking up for some reason
doh
...
remove unused from lock
ZTS build fixes
ZTS fixes
async add, fix async test, ammend globals, remove unused functions
correction
remove has_lock, unused
strip everything down to the minimum, tidy up the API
organize my thoughts re async stuff
async stuff
tidy whitespace
not here, somewhere else
correction to slam defense mechanism
expose num_slots
clear cache on USR1 signal to process
correction to that