starting to rework the editable question view
add bootstrap files
starting on parts
Merge branch 'master' into bootstrap

Conflicts:
	editor/templates/base.html
	editor/templates/question/editable.html
move variable delete button
Merge branch 'master' into bootstrap
starting on question parts
Merge branch 'master' into bootstrap
still working on parts
more parts, more styling
Merge branch 'master' into bootstrap
bootstrap: choices for 1_n_2 parts; input labels are clickable
bootstrap: m_n_2 and m_n_x parts

I've just plugged in the old choices/marks matrix thing for m_n_x. I'll have another look at it later.
bootstrap: gaps and steps in part list
bootstrap: question tags and extensions
Merge branch 'bootstrap' of github.com:numbas/editor into bootstrap

Conflicts:
	editor/static/css/question/edit.css
add a header for the question name input
bootstrap: more fiddling with layouts and so on

fun fact I just learnt: clicks on the "toggle rich text editor" button sometimes made the page refresh. That was because the default action for buttons is "submit", so when they're inside a form it gets submitted.
Set type="button" to stop it happening.
bootstrap: question edit view is finished!

This adds drag and drop of variables, function definition error messages, and some twiddles.
remove old stuff from question editable template