timerd: get rid of unused CTimerd::TIMER_NEXTPROGRAM

This event should be completely obsolete (it was used before
EIT-update was working correctly), so get rid of it in the code.
For now it is just commented out, until further testing is done.
zapit: improve the lockPlayBack "nonblank-Hack"
reduce direct dependencies on timerdclient.h

Include timerdtypes.h instead of timerdclient.h where feasible,
add direct instead of indirect includes of timerdclient.h where
necessary. This reduces the number of files which depend on
timerdclient.h from 134 to 16.
Add/update copyright notices in the affected files.
timerdclient: remove EVT_NEXTPROGRAM

...and EVT_ANNOUNCE_NEXTPROGRAM.
These are only internal API, so no incompatibility should occur.
timerd: rename TIMER_NEXTPROGRAM

To ensure it is no longer used, rename it to __TIMER_NEXTPROGRAM.
It cannot be removed without breaking compatibility, since it is
part of the API (the integers values of enum CTimerEventTypes are
written to timerd.conf)
scannit: fix printf format