Add EXP Chronology page
Simplify retrieval of fields
delete empty tests
Add total_exp method to Assessement model
Merge pull request #322 from wangqiang1208/features/my_courses_fix

delete empty tests
Reduce number of queries
Reorder columns
Merge pull request #317 from kxmbrian/exp-curve

Add EXP Chronology page
Merge branch 'development' of github.com:Coursemology/coursemology.org into Deploy