Update 'BigWigFileViews' code and man pages.

- coverage,BigWigFileViews-method now returns
  unaltered coverage (no transformations, summaries)
- summary,BigWigFileViews-method now calls 
  summary,BigWigFile in rtracklayer


git-svn-id: https://hedgehog.fhcrc.org/bioconductor/trunk/madman/Rpacks/GenomicFileViews@87494 bc3139a8-67e5-0310-9ffc-ced21a209358
Merge branch 'local-hedgehog'