Process all innocent commands immediately (fixes pause/resume)

Process all innocent commands immediately (fixes pause/resume)

To prevent that commands received during thinking will halt command
processing,eclipsing later instant commands, all commands that merely
alter a settings value in adapter or engine are now immediately executed.
UCI engines should be able to handle 'setoption' commands even during
thinking, so explicit or implicit (easy/hard) settings changes are
immediately relayed to the engine as well.
 The 'pause' and 'resume' commands are now also treated immediately;
waiting with that until the engine is done thinking subverted the
intention of the 'pause' command.
 Commands that would never be sent when an engine is thinking are still
left with the commands that require thinking to complete, as for those
thisdoes not matter.