Consensus secondary structure annotation rows for sequences with multiple sources of structural data

For sequences with multiple possible structures, colour by annotation fails if more than one structure is loaded for the sequence. JAL-3986 discusses an improvement to the colour by annotation routine in order to quickly address the problem, but ideally, rather than show an aggregate of all annotations of the same time (ie secondary structure), we should provide a real consensus secondary structure assignment. This could be shown by default, rather than individual rows for each structure (and chain) associated with a sequence.