Merge pull request #95 from dimagi/cleanup

refactoring related to types; also allow field list in groups
make question name and icon part of the mugtype definition, and refactor to enable that
single point of truth for question type slug
remove insane nesting of closures in parser
encapsulate getting itext reference from tag
convert formhub labels to commcare labels

this converts any <input readonly="true()"> to a <trigger>.

This could be problematic if any manually-created forms or forms created
by another tool use an <input readonly="true()"> in a way that's not
compatible with just switching to a <trigger>, but seems unlikely that
this happens.
fix choice default value broken after refactoring

mug.typeSlug is no longer defined manually in the mugtype
definition.  It's now just the mugType class name, and is set after
mug creation in a wrapper.  (We eventually, if it's ever worthwhile,
want to switch to prototypes and instanceof and get rid of typeSlug
altogether -- probably the only real justification would be using
prototypes to make long form loads faster by not creating duplicates of
every function on every mugtype object.)

This caused a problem in this one instance where during mug creation
typeSlug was referenced.  Moving the value definition to a better place
fixes.
Merge pull request #105 from dimagi/fix-choices

fix choice default value broken after refactoring
handle being able to show different icons based on the mugType's parent type (e.g. single-choice vs. multi-choice)
handle icon tweaks on changing question type
naming convention
rename event
update mug children at the very end
don't remove unreferenced itext
Merge pull request #106 from dimagi/multi-square

show checkbox icon for multiple choice items instead of circle
temporary mask for a bug where formdesigner.controller.getMTFromFormByUFID does not get the correct mugType from the mugTypeMaker
Merge pull request #107 from dimagi/hidden-val-mask

temporary mask for hidden value icon bug
Merge pull request #110 from dimagi/qr-code

remove insane nesting of closures in xform parser
compute width after resizing
Merge pull request #115 from dimagi/qpane-fix

compute width after resizing $formdesigner