#389 need visual flag for splices not on GT/AG

[Brian O.]

Lynn Crosby suggests the following (instead of the more general splice
site addition described after this):

Apollo should have a visual flag for splices for which the cDNA alignment
cannot be matched PRECISELY to a GT/AG. In some cases, it may be close
and sim4 may have fudged the alignment by a few bases; in other cases the alignment is so far from at GT/AG that it is shown as an atypical splice.

These need to be marked by BOP so that Apollo can show some visual
indication.