Added more scenario types

Added Resource-Role Scenarios and Resource Scenarios
Significant changes to the language to match the RBAC terminology more
closely

Addition of a few validation checks
Merge branch 'master' of https://git@github.com/lmcmontrieux/rbacDSL.git

Conflicts:
	uk.ac.open.rbacDSL/model/generated/RbacDSL.ecore
	uk.ac.open.rbacDSL/model/generated/RbacDSL.genmodel
	uk.ac.open.rbacDSL/src-gen/uk/ac/open/RbacDSL.xtextbin
	uk.ac.open.rbacDSL/src-gen/uk/ac/open/parser/antlr/internal/InternalRbacDSL.g
	uk.ac.open.rbacDSL/src-gen/uk/ac/open/parser/antlr/internal/InternalRbacDSL.tokens
	uk.ac.open.rbacDSL/src-gen/uk/ac/open/parser/antlr/internal/InternalRbacDSLLexer.java
	uk.ac.open.rbacDSL/src-gen/uk/ac/open/parser/antlr/internal/InternalRbacDSLParser.java
	uk.ac.open.rbacDSL/src-gen/uk/ac/open/rbacDSL/RbacDSLFactory.java
	uk.ac.open.rbacDSL/src-gen/uk/ac/open/rbacDSL/RbacDSLPackage.java
	uk.ac.open.rbacDSL/src-gen/uk/ac/open/rbacDSL/Scenarios.java
	uk.ac.open.rbacDSL/src-gen/uk/ac/open/rbacDSL/impl/RbacDSLFactoryImpl.java
	uk.ac.open.rbacDSL/src-gen/uk/ac/open/rbacDSL/impl/RbacDSLPackageImpl.java
	uk.ac.open.rbacDSL/src-gen/uk/ac/open/rbacDSL/impl/ScenariosImpl.java
	uk.ac.open.rbacDSL/src-gen/uk/ac/open/rbacDSL/util/RbacDSLAdapterFactory.java
	uk.ac.open.rbacDSL/src-gen/uk/ac/open/rbacDSL/util/RbacDSLSwitch.java
	uk.ac.open.rbacDSL/src-gen/uk/ac/open/serializer/RbacDSLSemanticSequencer.java
	uk.ac.open.rbacDSL/src-gen/uk/ac/open/services/RbacDSLGrammarAccess.java
	uk.ac.open.rbacDSL/src/uk/ac/open/RbacDSL.xtext