pass ellipsis to scale_x_continuous

[sam217pa]

Hi,

(This is a really minor pull request.)
I found that I needed to manually make some tweaks to scale_x_sequnit, like setting limits.
Just passing the ellipsis to ggplot2::scale_x_continuous does the job.

This edit was tested locally; it works, unless you explicitely pass breaks to scale_x_sequnit.
Do you think it need to be taken care of?

thanks for ggbio; it is pure gold.

[lawremi]

Ideally it would check for breaks (or labels). Anyway, please update the man page. Thanks for the contribution.

[sam217pa]

Done.

I added my name to authors in man page; don't know if it is ok with Bioconductor's policy ?
I don't mind not being mentionned for such a minor contribution.