Add downloaded packages in petsc.  Remove pips from dolfin.
Add build script to readme notes.  Remove old formulae from tmp
directory.
Fix README.  Decomment petsc.rb.
Fix minor typos in README
Update dolfin.rb
Update README.md

Add env=std to the petsc install
Update README.md
Update README.md
Update README.md
Update README.md
Merge pull request #1 from lukeolson/master

Update petsc to include downloads.  Change dolfin.rb to use pip for some python

Tried and tests.  Still some issues.