IDE-1607 For multiple wrappers show quick type hierarchy popup
IDE-1607 Better method matching
IDE-1503 Integrate xml-search into Liferay-IDE

- simplify validtion preferences to five types
- create a new class LiferayDescriptorBaseValidator insteadof DefaultDOMNodeValidator as
  the base validator of all descriptor validators
- add liferay custom markers and validators
IDE-1503 Intergate xml-search into Liferay-IDE

- Removed old descriptor validators
- Moved descriptors and reference declarations from ui to core plugin,
  for the unit tests