JBIDE-13148 Introduce an "strict taglib" validation

Strict Taglib validator is created. JUnit Test is created for the issue.

	modified:   jsf/plugins/org.jboss.tools.jsf/META-INF/MANIFEST.MF
	modified:   jsf/plugins/org.jboss.tools.jsf/src/org/jboss/tools/jsf/web/validation/JSFSeverityPreferences.java
	modified:   jsf/plugins/org.jboss.tools.jsf/src/org/jboss/tools/jsf/web/validation/StrictTaglibValidator.java
	new file:   jsf/tests/org.jboss.tools.jsf.test/projects/JSFKickStartOldFormat/WebContent/strictTaglibValidation.xhtml
	modified:   jsf/tests/org.jboss.tools.jsf.test/src/org/jboss/tools/jsf/test/JsfAllTests.java
	modified:   jsf/tests/org.jboss.tools.jsf.test/src/org/jboss/tools/jsf/test/validation/ELValidatorTest.java
	new file:   jsf/tests/org.jboss.tools.jsf.test/src/org/jboss/tools/jsf/test/validation/MarkerAssertUtil.java
	new file:   jsf/tests/org.jboss.tools.jsf.test/src/org/jboss/tools/jsf/test/validation/StrictTaglibValidatorTest.java