+ * Return the alignment column for a sequence position * Return the alignment
+ * position for a sequence position
+ *
+ * @param pos
+ * lying from start to end
+ *
+ * @return aligned column for residue (0 if residue is upstream from
+ * alignment, -1 if residue is downstream from alignment) note.
+ * Sequence object returns sequence.getEnd() for positions upstream
+ * currently. TODO: change sequence for
+ * assert(findIndex(seq.getEnd()+1)==-1) and fix incremental bugs
+ *