/**
* Computes the column and sequence row (and possibly annotation row when in
* wrapped mode) for the given mouse position
+ * <p>
+ * Mouse position is not set if in wrapped mode with the cursor either between
+ * sequences, or over the left or right vertical scale.
*
* @param evt
* @return
/**
* Returns the aligned sequence position (base 0) at the mouse position, or
* the closest visible one
+ * <p>
+ * Returns -1 if in wrapped mode with the mouse over either left or right
+ * vertical scale.
*
* @param evt
* @return