Omit itext ID if there is no itext

Also fix minor typo.
Make label (trigger) type changeable
Show change type button on Choice and Hidden Value

...but don't allow type to actually be changed. Hiding the button impedes usability because (a) there is no indication of the question type on the form and (b) the copy button moves to where the change type button normally is. Disabled buttons are hard to read, which explains why we didn't go that way.
Minify js
Merge pull request #214 from dimagi/fix-develop

Fix bugs on develop branch
Merge remote-tracking branch 'origin/master' into develop

Rebuilt vellum.min.js

Conflicts:
	dist/vellum.min.js
Merge pull request #216 from dimagi/develop

Merge QA-driven fixes into master