Create the verifyElementDifferent control

Relates #440
Add Cerberus documentation on new controls

Relates #440
Add controls verifyIntegerEquals & verifyIntegerDifferent

Relates #441
Add documentation on new controls

Relates #441
Merge branch '440'
Merge work on isue #441

Conflicts:
	source/src/main/java/org/cerberus/database/DatabaseVersioningService.java
	source/src/main/java/org/cerberus/serviceEngine/impl/ControlService.java