JavaBuilder#isWorthBuilding

The new marker API from Bug 570914 allows to create markers with
attributes and therefore avoids sending out resource change events for
every attribute change.

Includes an update of the  required resource API version.

Change-Id: I6dfbbfbb3ed1fe6fe499549c5da9a4eb6e36679b
Signed-off-by: Lars Vogel <Lars.Vogel@vogella.com>