Create SWTBot integration tests for tern related features

There should be set of SWTBot tests that would cover functionality related to tern.java and angularjs-eclipse integration. These tests would simplify migration to new tern.java and angularjs-eclipse releases.

Current process for migration to new version of tern-java/angularjs-eclipse is manual. Steps below describe current approach:
1. Manual mirroring of latest tern-java/angularjs-eclipse versions to local filesystem;
2. Build jbosstools-jst with local mirrors and run JUnit tests;
3. Install latest tern-java and angularjs-eclipse form mirrors done in (1) into JBDS nightly build from master branch (it has open version range for tern features) and restart;
4. Run manual tests;
5. If (2) and (3) idenify no problems then local mirrors should be published to http://download.jboss.org/jbosstools/updates/requirements/tern and http://download.jboss.org/jbosstools/updates/requirements/angularjs respectively;
6. Update jbosstools-jst with new versions for tern-java/angularjs-eclipse and push local branch to upstream

With step 4 implemented as SWT bot tests and automated mirroring for tern-java and angularjs-eclipse (see jenkins job here https://jenkins.mw.lab.eng.bos.redhat.com/hudson/view/All/job/jbosstools-tern-mirror/) we can fully automate the process above.

QA also can skip step (1) and just use external p2 repos:

• http://oss.opensagres.fr/tern.repository/1.0.0-SNAPSHOT/
• http://oss.opensagres.fr/angularjs-eclipse/1.0.0-SNAPSHOT/

in step (2) by building jbosstools-jst as:

mvn clean install -Dtern.repo.url=http://oss.opensagres.fr/tern.repository/1.0.0-SNAPSHOT/ -Dhttp://oss.opensagres.fr/angularjs-eclipse/1.0.0-SNAPSHOT/

and installing latest versions for step (3).