Thread events do not ignore "internal" threads.

[ericsnowcurrently]

The handler for CMD_THREAD_CREATE hides "internal" threads from VSC (i.e. do not emit an event). An internal thread is one for which the name starts with "pydevd." or "ptvsd.". The handlers for the other 3 thread events (_KILL, _SUSPEND, _RUN) currently do not hide internal thread events. This means that the debug client (e.g. VSC) may be confused when it receives, for example, a stopped event for a thread it does not know about.

Either internal threads should always be hidden or they should never be.

[karthiknadig]

#135 This should fix some of those issues.

[karthiknadig]

In my change, I am making sure that we only report about the thread that are in the map. They should get added to the map only if the are not "pydevd" or "ptvsd" threads.

[ericsnowcurrently]

Yeah, I think that should do it. :) Thanks!