Yet mode debugger improvements

As part of our move to XDebug we are adding new features that were not available in DBG.

The first one is support for the local variables watch window. XDebug has the ability to retrieve this list and we are adding support for it.

The second feature/bug fix is the ability to keep breakpoints working after you made modification in the code. Before those breakpoints needed to be reset. Right now the fix only applies to XDebug but we are going to try to fix it on DBG as well.

The next VS.Php 2.4 build will contain these changes.