cspect: Get Sprite Patterns during debugged program being run

[maziac]

Note: In the develop branch the program lives the running state if some DZRP command is sent so this cannot happen here anymore.

Nevertheless it is still unclear why this is a problem:

If the debugged program is being run and one presses the sprite patterns reload button a few times then the debugged program starts to behave strange.
The z80-sample-program e.g. is still running but the output to the screen does not happen anymore.

I tested a bit: when I move the GetSpritePatterns function into the Tick() routine the strange effect is gone. So this is most probably a threading issues.
Unfortunately I cannot simply move all message responses in the Tick routine as it would require 20 ms per message which is too much.

Need to find another clever way.
(Asked Mike for a faster Tick() method)