Fixing broken code that lead to no check for breakpoint condition.

* Extending ShouldBreak with frame, so expression can be evaluated for any isolate.
* Moved call to ShouldBreak out of DebuggerManager to FlashInterface.
* Small fix to ExpressionContext to always return proper isolate id.
* Better check on checking suspend reason for main worker and use ShouldBreak to fire BreakpointEvent.
* Moved isolate suspend() call to the debugger worker thread.
* Handle all suspend reasons of workers BreakEvent
Merge pull request #506 from zobo/fix/bp-exp-workers-dev2

Fixing broken code that lead to no check for breakpoint condition.