core: simplify businessentity equals() methods [part 1]

Instead of manually doing a null-safe comparison for each business
entity, use ObjectUtils.objectsEqual().  Where applicable, optimize
the order of comparison by looking at the id field first.

The resulting code is more concise, easier to maintain, and doesn't
mask errors due to missing braces like the previous code did.

Change-Id: Ie9531a453a352619e8a6243ea1a5e4d0de4d1a45
Signed-off-by: Greg Padgett <gpadgett@redhat.com>