[infinitest-eclipse] Provide toolbar button to disable/enable

[Clasmir]

This is a great eclipse plugin but it has at least one major drawback. A race condition occurs when infinitest attempts to run tests while Maven is processing a build. This not only slows the build but causes the editor UI to stutter and hang for periods of time.

The best fix would be for the plugin to disable the scanner under specific conditions but that might be difficult to implement and support.

In lieu of this, having a simple toolbar button to disable/enable the scanning feature would be an acceptable compromise.