getActiveShell() sometimes returns null
This commit fixes #434.
added BrowserEditor #393
Fixed method ProjectItem.getChild(String) and updated test case #416
Changed test method's name to unique name for each run/config #420
getFirstPage returns page with index 0, fixes #431
Editor toolbar implementation (fixes #392)
SWT Utils refactored (fixes #386)
Adds support for adding custom run listeners
Fixes #438