Add comment to .cabal file saying what GHC 7.6.1 shipped with
Bump version number following new policy

We now keep the HEAD version numbers as values which would be suitable
for immediate release.
zap obsolete FIXME, fix typos
Provide a way for OS X users to indicate a preference for the GMP framework

We used to always use the framework if it existed. Now the make variable
GMP_PREFER_FRAMEWORK can be used to control whether the library or the
framework is preferred.

Fixes #7466.
Fix configure when we don't have a gmp library