Changed the StudentProject model to handle a dynamic amount of GradeRecords. This allows for a dynamic amount of moments where a StudentProject can be evaluated. Also included in this patch are changes to the status property that will help to enable PA's to withdraw StudentProjects from the program without the need for a developer to step in.

[nosetests]
exclude=pymox
with-coverage=1
cover-package=soc
cover-erase=1
cover-html=1
cover-html-dir=coverageResults
#debug=nose.plugins.cover