Dartdoc presentation fixes.
DartPresentableUtil test.
More fixes.
More fixes (getters, setters, constructors, etc).
Merge branch 'dartdoc_preview_fixes' of https://github.com/pq/intellij-plugins
dependency on markdownj
DartComponent.isAbstract() fixed, isConstructor() implemented
Merge remote-tracking branch 'origin/master'