Remove some excessive logging
Don't use flanking region when zooming to a locus string

IGV-2053
Fix problem with ReferenceFrame -- zoom calculation was not accounting for the width of the frame.  This matters for gene lists.  There was a "min/max" calculation done after setting the zoom, this is not neccessary if the zoom is calculated correctly.
Fix NPE problem in AbstractDataSource
Fix query string parsing so we are tolerant against stuff after a ? which isn't a=b
Modify TrackLoader so we examine file extensions more properly

Either use ResourceLocator.getTypeString() or getURLPath() (getTypeString strips gz, sometimes we need to keep that)

This handles URLs properly, remove the query string when checking for file type but loading from the full path.

IGV-2054
Workaround for the fact that BEDTools can't read blank files

If we try to export a blank feature file, add in 1 feature which is unlikely to overlap with anything. This should have the same effect as no features at all
Merge remote-tracking branch: upstream/master