add and edit challenge
fix edit challenge
transactional and push edit only if number or name changed
fix some coding convention issues
fixing some typos
indentation and handle for challenge with no exercises
for challenges that dont have any pdf
for challenges that don't have any pdf shouldnt set any value while submitting
Merge pull request #244 from egor83/master

Fixing unit tests problem (#232)
fix indentation
fix more of indentation
Merge remote-tracking branch 'upstream/master' into voting
Reacting to code review (#121)

Changes to GUI, unit tests.
fixes for adding challenges with no course/exercise
Merge pull request #241 from anubhavsinha/add-edit-challenge

add and edit challenge
course drop down feature
Merge pull request #246 from anubhavsinha/course_dropdown_new

course drop down feature
Reacting to code review (#121):

changes to GUI behaviour, some refactoring.
Reacting to code review (#121)

Changing error handling in RPC handler.
Merge remote-tracking branch 'upstream/master' into voting