all: introduce fwk/fsm.State and fwk.FSMStater
svc,tsk: implement fwk.FSMStater
hbook: first stab at a histogram service
all: add Context.Svc(name)
hsvc: non-conc-safe impl.
test: add hbooksvc test (sequential)
hsvc: add concurrency-safety
test: hbooksvc concurrency
test: hbooksvc concurrency (reduce load for drone.io)
test: hbooksvc concurrency (reduce load some more - for drone.io)
Merge pull request #31 from go-hep/dev/hsvc

Dev/hsvc