Save time by installing all the packages at the same time

using pip install -r requirements.txt is more efficient than doing all
the packages individually
Make the file paths more friendly to doing local development
A more comprehensive install guide, albeit specific to Suse linux?

i'm assuming 'zypper' is equivalent to 'yum' and 'apt-get'?
Deleting Exam removes associations from Videos

* Deleting an exam will first look up all the videos which have a
  foreignkey to it, and sets all their .exam properties to None. Then it
  goes ahead with the deletion.
  (closes #2043)
Merge pull request #2127 from Stanford-Online/jrbl-2043-delete-exam-deletes-relationships-too

Deleting Exam removes associations from Videos
Merge pull request #2049 from natea/master

Simplifying the install process for new developers and making it easier to work with local directories
initial travis CI configuration (#2133)
add xhtml2pdf to requirements
Add build status to top (travis) (#2133)
Only care about building python 2.7 (#2133)
add jenkins/setup.sh to script (#2133)
Merge branch 'master' of http://github.com/Stanford-Online/class2go into dca_new_working2
For #1000, fixes student score report issue and tidies some code on the
row colours feature for quizzes summary.