minor: one char comments fix
minor: clarify docs in one place
Introduced and then fixed a MAJOR bug where frozen lvars can reclvars can receive puts
Oops - fix whitespace problem caused by f68da4d30017a8f696febae3705d1ff23b67d75
Add -threaded to .cabal file for sequential executable build.

It seems weird that we need this to build the sequential version, but
they both use atomic-primops, so I guess we do.  (There's a link-time
error otherwise.)
Add incoherence to PureMap to get k-CFA-lvish.hs to build (cc #18).

Not sure if this is the right thing; it feels like a hack.
Get rid of outdated comments.
Add comment pointing to issue #18