Fix JsfAllTests.testIncorrectTags junit test

This test fail becouse xmodel don't loaded custom taglibs in time of loading VPE.
JsfAllTests.testIncorrectTags (from org.jboss.tools.jsf.vpe.jsf.test.JsfAllTests)
Failing for the past 5 builds (Since Unstable#218 )
Took 1 sec.
Error Message

there is not : "VPE:INCLUDE-ELEMENT" attribute

Stacktrace

junit.framework.AssertionFailedError: there is not : "VPE:INCLUDE-ELEMENT" attribute
at org.jboss.tools.vpe.ui.test.ComponentContentTest.compareElements(ComponentContentTest.java:136)
at org.jboss.tools.vpe.ui.test.ComponentContentTest.performContentTest(ComponentContentTest.java:95)
at org.jboss.tools.jsf.vpe.jsf.test.jbide.JBIDE3197Test.testIncorrectTags(JBIDE3197Test.java:27)
at junit.extensions.TestDecorator.basicRun(TestDecorator.java:24)
at junit.extensions.TestSetup$1.protect(TestSetup.java:21)
at junit.extensions.TestSetup.run(TestSetup.java:25)