Creates new SWTBot plugin tests for WatchDog

Makes basic structure for WatchDog tests. Also adds a test case that asks
whether the menu contribution is active.

Refs #21
Adds further refinements (javadoc)

Refs #21
Adds Tests for startup statistics.

Refs #21
Merge pull request #22 from TestRoots/UiTests

Ui tests (SWTBot)