Merge pull request #95 from jsyeo/jsyeo-fix-uninit-const

Fix uninitialized constant Training in _tabs
fix unable to comment due to cancan authorise problem
Merge pull request #97 from jsyeo/jsyeo-fix-uninit-const

Fix #96 and #98. s/Mcq/Assessment::McqQuestion
rename mcqs to mcq_questions for naming consistency
migrations for using acts_as_taggble_on
add gem acts-as-taggable-on
data migration script for using tables from acts-as-taggable-on
changes due to mcq question renaming
validate presence of necessary assessment fields
create simple_from tag input field, utilise jQuery token input library
create or update tags for question creation or updating
fix for tags and tag group controller and views
update course ability (use manage:all again)
lecturer and admin can manage course settings
create uncategorised tag group after creating course
fix mission and training column preference display
allow filter assessments by tags
random fix
fix duplication after change tags
put back update method in question controller