Recent upstream IRMP core versions introduced a "release" flag in
addition to the "repeat" flag. Prepare the decoder to present these
flags when libraries should pass them in results.
The flags' being orthogonal slightly complicates the logic which
constructs annotation texts. Do provide text variants for all previously
supported zoom levels, yet try to keep the implementation as simple as
possible: Match list lengths for simplified folding. Always print the
flags field even if none of the flags is active (kind of was done before
this change as well, just not visible). This approach easily accepts
more flags as needed in future versions.