fix double serving of assets in development env
fix edit role request error
Fix question no position & dependency bug after duplication
refine fixing
set dependency_id to nil if pos < depend_pso
reduce line length
Using a smart way to handle position
Also fixed the course duplication denpendency problem
Merge pull request #175 from wangqiang1208/bugfixing/course_duplication

Fix assessment duplication bug in duplicate page
add attr_accessbile to assessment answer model
Merge branch 'development' of github.com:Coursemology/coursemology.org into development
Merge branch 'development' of github.com:Coursemology/coursemology.org into Deploy