move jstreetypes to util
generate jstreetypes from question types

(and make fieldlist able to be a child of a group or repeat)
refactor jstree icon overriding to be more maintainable
remove further question type indirection
remove unused typeName attribute
single point of truth for question type slug
remove unused name property
make question name and icon part of the mugtype definition, and refactor to enable that
add missing jstree types
fix order of includes in tests
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.