TEIIDDES-1734: Upgrades the Target Platform to integation-stack 4.1.0

* target-platform/pom.xml
 * Upgrades the TP pom to merge in the integration-stack 4.1.0

* teiid-designer.target
 * Regenerated target used as TP by both maven and eclipse builds

* **/MANIFEST.MF
* **/feature.xml
 * org.junit4 has been renamed to org.junit
 * versions adjusted to have 4.11.0 as the minimum since the TP includes
   both 4.10 and 4.11

* WSDLSchemaExtractor
 * EMF upgrades causes test failures since wsdlURI.isFile() no longer works
   with standard file paths due to the EMF URI not being absolute and not
   including a file:// protocol.
 * Simplifies the test so that a check on the wsdl uri string is made for
   an http prefix. Since credentials are only essential for http urls then
   this is a sufficient test.
TEIIDDES-1734: Migrate to new locus update site

  * Migrate plugins to depend on the new JBT locus update site