Minor update. Handle "Permission denied" on directories more gracefully.

Trapped the "Permission Denied Error" when trying to lsseq a directory without it having the appropriate execute permissions set.

So instead of erroring out with a python exception trace, lsseq now handles the exception gracefully, prints an appropriate warning message (unless --silent or --quiet is on) and added another bit to the error flag output. New error code 16 which you can bit-wise or the error code generated returned to see if this warning was tripped.