INSTALL.md: Update MacPorts instructions

The MacPorts port gsl-devel is older than the gsl port and both provide the same files. See http://stackoverflow.com/questions/19372410/trouble-installing-gsl-using-macports.
Merge pull request #52 from neverpanic/patch-1

INSTALL.md: Update MacPorts instructions
Field t constraints, general pinvTol, and pinv = pinvTol 1
changes, thanks
move changes.md to CHANGELOG
reimport Vector.fromList instead own implementation
Merge pull request #56 from s9gf4ult/master

reimport Vector.fromList instead of own implementation
rename variables so Prelude.join will not cause problems

* background:
http://www.haskell.org/haskellwiki/Functor-Applicative-Monad_Proposal#Current_stage:_Prepare_GHC

* the change happens in ghc-7.10, and these changes fix warnings with 7.8
build with ghc-7.7

this is probably the wrong approach and likely it breaks code that
mentions the BoundsOf/ContainerOf
Merge pull request #60 from aavogt/master

small changes for compatibility with newer (to-be released) ghcs
bump version and thanks
absolute tolerance added to C interface for integration
zero absolute tolerance in the integration routines provisionally changed to 1E-12
Add freebsd library config info
Merge pull request #63 from mwm/master

Add freebsd library config info to cabal
OS X Installation via Homebrew
Update INSTALL.md
Merge pull request #66 from tfgit/master

Making installation easier for OS X.
thanks and tested with 7.8.1