hammer2 - locking revamp
* Temporarily remove hammer2_ccms.c from the build and remove the ccms
container. The CCMS container will be used again when we get cache
coherent in, but for now it isn't needed.
* Replace the ccms state lock with a mtx lock and move
into hammer2_chain_core.
Note that the mtx lock being used here has abort and async locking
support and these features will be required by HAMMER2.
* Replace the ccms spin lock with a normal spin lock and move
into hammer2_chain_core.
* Refactor the OS locking interface to use hammer2_* prefixes for easier
porting.
* Use a shared spin lock for the ONFLUSH bit update instead of an exclusive
spin lock.