[cctbxbb] updated project docs

FYI, I finally updated the online documentation for the first time since switching the project backend. Included in this is the corrected link for the SVN browser, which for the record is now: http://sourceforge.net/p/cctbx/code/HEAD/tree/trunk/ (I find this somewhat over-engineered, but the old URL only shows the frozen repository as of early March, so we don't have a choice.) If anyone notices broken stuff, please let me know. -Nat