add a parse string function to enable #<> in code editor
fixing the answer grading not showing bug in gradings view
change answer.save to answer.specific.save
add result fields to both answer and coding_answer
Merge pull request #216 from wangqiang1208/bugfixing/auto-grader-output

fixing the answer grading not showing bug in gradings view
fix training tab duplication bug
re-order tab logs
soft delete tabs
add deleted_at to tabs table
run migration
Merge pull request #218 from wangqiang1208/bugfixing/tab-soft-delete

tabs soft delete implementation
Merge pull request #217 from wangqiang1208/bugfixing/course-dup

fix training tab duplication bug
fix new contest survey 'no such action' bug
set is_contest field in survey default to false
Fixed embarrassing typo
Merge pull request #221 from yangshun/public-typo

Fixed embarrassing typo
using regular expression to do string parse
Merge pull request #212 from wangqiang1208/bugfixing/code-editor-display

add a parse string function to enable #<> in code editor
Merge pull request #220 from wangqiang1208/bugfixing/survey

fix new contest survey 'no such action' bug
show all the explanations if answer is correct
change implementation to show only for MRQ questions
fix generating new section bug
Merge pull request #224 from wangqiang1208/bugfixing/survey

fix generating new section bug