Rename MaxCounter -> MaxPosInt; tweak docs a little.

Also expose `fromMaxPosInt`.
Start sketching out Data.LVar.Counter. Almost nothing there yet.
minor mod to race detector testing setup
Repair test failure in jenkins build 735
Bump LVish version to 1.1.1.5 for recent bugfixes
Merge branch 'master' into 2.0

Conflicts:
	haskell/lvish/Data/LVar/MaxCounter.hs