Current implementation of DAR has few limitations:
- whole page is processed even if the target area was already rendered.
- support only area which exist in JCR
Check for "mgnlArea" should go into AreaFilteringListener.init()
- The rendering of areas/components outside of the target area should be skipped.
- We could support not only areas existing in JCR but also those defined in template definition.
- Add possibility to disable check for area existence to be able to render all areas.