Bug 440354 - [jobs] Don't call belongsTo with null in JobManager#join

Implementations may not expect a null family.

Signed-off-by: Robin Stocker <robin@nibor.org>
Bug 432079 - Clean up org.eclipse.core.jobs

Generics and un-necessery casts cleanup in
eclipse.platform.runtime/tests

Change-Id: Ia10647eb3f75fdde48bcc91e8e7ab74d720cc3ef
Signed-off-by: Thirumala Reddy Mutchukota <thirumala@google.com>
Bug 432049: JobGroups API and initial implementation.

Change-Id: Id1162cd9f084128db075780a15fb537e761722b2
Signed-off-by: Thirumala Reddy Mutchukota <thirumala@google.com>
Signed-off-by: Terry Parker <tparker@google.com>
Moved all job group lock access into the job group class
Minor cleanup, making unchanged fields final
Minor cleanup