Added a section on dependencies.

Added a section on installing dependencies.  Still working on getting rubygems installed manually.  In particular, autolibs needs to be disabled to be able to install offline.
Refine dependency rules

Reworking dependency installation rules so they work.
Finished instructions for manual rubygems

Finished instructions for manually installing rubygems offline.  If the ruby install fails to install rubygems, the only obvious way to try again is to reinstall -- which takes time.
Merge pull request #195 from rhinton/master

Updated offline install instructions