make zoom changes register when going from full chromosome to 10 Mb
range.
Merge pull request #126 from Traksewt/zoom-wide-angle-tiers

make zoom changes register when going from full chromosome to 10 Mb range
Fix warning about protocol-relative prefixes.
Fix bug booting workers with protocol-relative prefix.
Use credentials for BAI probe if needed.
Fix histograms in cases where score range doesn't include the origin.
Allow URLs with query strings.
Fixed bug which prevented trampolining to the next chunk of a BAM file.