ported IsabelleImages to Scala;
also using ResourceManager instead of the plugin image cache
ported TheoryOutlinePage to Scala;
reworked the approach by splitting Structure and Raw types into separate content/label providers as well as using immutable value classes with lazy fields
display the status of session (e.g. "Isabelle prover is not running") at the top of Outline page
helper with delay actions
listen to document changes and update Structure outline accordingly
listen to changes in Raw markup (command changes) and update outline accordingly
some support for UI preferences
action to toggle Structure/Raw tree in outline
select and reveal Outline selection in the TheoryEditor
Merge branch 'outline' into isabelle2013