Revert "re-render markdown directive on readonly change"

This reverts commit 7e226b37344183d98c4cf3685f2c52897561a36e.
Revert "Revert "re-render markdown directive on readonly change""

This reverts commit 5a81a827cbcd117faa2b351492767fc977329431.
Merge branch 'develop' of https://github.com/hypothesis/h into develop
Merge branch 'develop' of https://github.com/hypothesis/h into develop
Added missing drag-watch
Merge pull request #326 from hypothesis/262-hotfix

fix #262