FORGEPLUGINS-148 Upgrade to java client 2.5.0

Corrected the RestService API usage to reflect changes done for
JBIDE-15429.

Also corrected the use of ICartridge and related classes as done
for JBIDE-13866.
Fixed ressource leak in load()
Merge branch 'BugfixPropertiesLoad'
Fixed imports and a NullPointerException on baseUrl (and optimized a few
lines)
Merge branch 'BugfixNpeTail'
Merge remote-tracking branch 'VineetReynolds/FORGEPLUGINS-148'

Conflicts:
	src/main/java/com/redhat/openshift/forge/OpenShiftPlugin.java