do not link with gtest

 -- it's supposed to get compiled in via #include
fix "brew tap" instructions so they work
Merge pull request #117 from pzinn/master

Changes the behavior of "degree" when variables have degrees != {1}
add 'binomial' method for ring elements
Merge branch 'master' of github.com:Macaulay2/M2
remove instructions from makefile

because they conflict with those in INSTALL
clarify INSTALL
Merge remote-tracking branch 'upstream/master'