Update installing.scrbl

Replaced "Racket" references to "DrRacket"
Update running.scrbl

Comments on emacs implementation on mac
allow arrow annotations with zero arguments
add syntactic support for type parameters throughout annotations, fix buggy cases in typecheck for a-any and a-blank, fix documentation of what a-app is. closes #84
add missing test cases for 5f47c67, relates to #84
add support for data type parameters being used in constructors, closes #83
Merge pull request #79 from dpcollin/patch-7

Update running.scrbl
Merge pull request #77 from dpcollin/patch-5

Update installing.scrbl
vary-prettier, I suppose.
Merge branch 'master' of github.com:brownplt/pyret-lang
intermediate commit to move over to master from bad wd
Merge branch 'master' of github.com:brownplt/pyret-lang
intermediate commit to move over to master from bad wd
some annoying leakage from other branch, plus data-eq stuff
data-eq
some negative tests
merge w/master