[JBoss AS7] add read-write config update delegate which reads resource config prior applying update and applies changes only (currently supports only simple properties

(cherry picked from commit 3d0571af3f465c6d47567483ebc0148a514e6851)
Signed-off-by: Lukas Krejci <lkrejci@redhat.com>
[Bug 1080833]

For EJB3 subsystem we now apply only configuration properties that differ
from current configuration.

(cherry picked from commit c70267492ec430e4ef1218065ffc4220c2ba7e51)
Signed-off-by: Lukas Krejci <lkrejci@redhat.com>