modifying start/end via the sequence ID edit box can cause exceptions and corrupt sequence feature display

Modifications of the start/end numbering by inserting a new '/start-end' phrase at the end of a sequence's ID in the edit sequence ID text box are not properly validated (ie the stated length can be less or more than the actual number of symbols present in the sequence) - leading to exceptions and problems with feature display:

1. Cigar based AlignmentView creation can fail with an exception raised about inconsistencies between the alignment's start/end position and the dataset sequence's start/end.
2. If (end-start+1) is shorter than the actual non-gap character symbol string length then sequence features after the stated end position will not be rendered. If end<start then no sequence features are rendered at all.

Workarounds - which will result in the displayed end position being re-calculated correctly:
1. copy and paste the alignment into a new window.
2. export the alignment to a flat file and re-import.