Update for window() and seqselect()

- Window works as it should
- seqselect I am not sure how it is suppose to work - the documentation
I have seems to indicate that you specify two ranges and extract from
the GRanges the GRange that have ranges that start within either of
those lists; however, this is not what I would have expected, but rather
that start is compare to the first list and second range was for the
finish field... those GRanges that both start and end within the two
specified ranges would be returned... this isn't what is going on but it
should be simple to change if that is how it should be implemented.