Make cached stateClasses be a ThreadLocal
Make cached stateClasses be a ThreadLocal

In Erjang, we need to run multiple Kilim
"instances" concurrently, so we need this
static state to be thread-local.

KobeFeng/kilim,taowen/kilim,nqzero/kilim,nqzero/kilim,ericmm/kilim,ericmm/kilim,zofuthan/kilim,aruanruan/kilim,njucslqq/kilim,KobeFeng/kilim,taowen/kilim,njucslqq/kilim,aruanruan/kilim,zofuthan/kilim