Several references to long gone `MARLINDEBUG` compiler option

[tmadlener]

There are several processors and an example from which most of these are probably derived that still mention a MARLINDEBUG compiler option, e.g.

Marlin/examples/mymarlin/src/MyProcessor.cc

Lines 121 to 125 in dd3dc6b

	//-- note: this will not be printed if compiled w/o MARLINDEBUG=1 !
	streamlog_out(DEBUG) << " processing event: " << evt->getEventNumber()
	<< " in run: " << evt->getRunNumber() << std::endl ;

This option hasn't existed in a long time and is slightly confusing if people are looking at why their processor doesn't produce output on DEBUG.

Whether that option exists or not is actually full determined by the streamlog library and how that was compiled, most importantly, here:

https://github.com/iLCSoft/iLCUtil/blob/cf58a5902010ccbcc318338132d357635d6a7c54/streamlog/source/include/streamlog/baselevels.h#L24-L30