fixed some issues with level inheritance and serialized properties.
(LevelsController#show working for Match and Multi again)
Fixed LevelSource factory, added test.
Merge pull request #875 from code-dot-org/factory_fix

Fixed LevelSource factory, added test.
updated custom levels
Merge pull request #874 from code-dot-org/fix_show_match_multi

fixed some issues with level inheritance and serialized properties.
Merge branch 'finished' of github.com:code-dot-org/dashboard into finished

Conflicts:
	config/scripts/custom_levels.json
fix error in multi
Add IE9 testing tip
restore initial dirt in custom levels
remove invalid level
support zero nectar
code review feedback
Merge pull request #876 from code-dot-org/zeroNectar

support zero nectar
Automatically built
Merge pull request #877 from code-dot-org/finished

deploy to delivered