jbpm-workitems: use cxf-api instead of cxf-bundle-jaxrs

 * the cxf-bundle-jaxrs is bundling basically everything
   cxf related and also bring a lot of other transtitivite
   deps, which is not what we want. To satisfy the
   illegal-transtitive-dependency-check it is enough to
   depend just on cxf-api.

 * removed the resteasy-jaxrs-api dep. as it collides with
   the CXF stuff (e.g. NotSuchMethodError) and it seems
   it not needed anyway (tests pass and the
   transitive-dependency-check too)
jbpm-human-task-core: JAXB/JSON serialization correctness (because of kie-remote-jaxb-gen issues)
JBPM-4483 - error on broadcasting signals - test cases
adjustemnts to timer based test to not cause false alarms
jbpm-human-task-core: JAXB/JSON serialization correctness (because of kie-remote-jaxb-gen issues)
Fix tests in CI by using local maven repo in target/

 * using clean repo for every build (instead of the
   shraed one in ~/.m2) fixes the failing tests in CI

 * having the local repo in target/ also greatly
   improves the isolation of the tests. They are
   less dependent on the current state of ~/.m2 on
   the particular machine
Fixed a bug in ProcessSubTaskCommand where checking whether a subtask was equal to the current task being processed
- this happens when Task Id was > than a certain number because of a Java AutoBoxing issue.
- see (http://stackoverflow.com/questions/3130311/weird-integer-boxing-in-java).

Now uses .equals() instead of ==.
BPMSPL-84 - variableId=value functionality
removed jpa callbacks to serialize content of session, process instance and work item and use tx sync instead
updating extension model - update to meta data and meta value entries
updating extension model - corrected file/class name mismatch
BPMSPL-84 - variableId=value functionality bugfix
- javadoc corrections
BZ-1147965 - EJB interface missing method to get the content of an attachment
BZ-1148304 - Terminating process instance does not stop a timer event which has already started
BZ-1148473 - JBPM Spring+Hibernate+LocalTX Initialization IllegalStateException: This session was previously disposed DisposedReteooWorkingMemory
BZ-1149068 - Although a User Task has already claimed, another user can still get the Task using getTaskAssignedAsPotentialOwner()