Use CPM with dead time compensation for all standard output. Removed the
three separate cpm-related commands on the serial interface: getcpm now
returns everything in one structure - our link is at 115200, this is not
an issue at all.

Better documentation on Geiger.cpp
Implement {"get":"cpm"}, remove commented-out code (that' what git is
here for, no need to leave old commented stuff laying around)
Merge pull request #60 from elafargue/deadtime

Deadtime