Some I18N cleanup, every little bit helps reduce what translators have to deal with.

(cherry picked from commit 6085e3980148396c963c8e876eb0f4b6a4b0633c)
Signed-off-by: Thomas Segismont <tsegismo@redhat.com>

Conflicts:
	modules/enterprise/gui/coregui/src/main/java/org/rhq/coregui/client/admin/topology/AgentTableView.java
	modules/enterprise/gui/coregui/src/main/resources/org/rhq/coregui/client/Messages.properties