add drag and drop in chpice quiz edit
minor fix drag and drop
refactor drag and drop
don't use observes because not working
Update guide.rst
rename static_content to options
fix drag and drop in sort quiz
 #EDY-1580 fixed
fixed tooltip typo
Merge pull request #4 from StepicOrg/feature/content-refactoring

Content refactoring
wysiwyg for free-answer quiz
prepare dataset quiz for new submission list
minor
fix doc typo
Int inputs hotfix.
 #EDY-1668 in progress
Static updated by hands.
Lazy migration for int->str in Choice and Code.
Revert "Lazy migration for int->str in Choice and Code."

This reverts commit 8442bfc2f0d81c3015ab9a5799533075bbb10256.
Revert "Static updated by hands."

This reverts commit 174a06ad4ed8377499dcabddd1beedad7355d23a.
Revert "Int inputs hotfix."

This reverts commit 38db0333756ca463fe69eca9e8d4db405126238f.
soften schema verification (integers passed as string)