Add ability to load files with commas in them

Since we can load comma-separated lists, the user must put quotes around the file name if it has quotes in it (same as with spaces)

IGV-2073
Fix bug where max zoom didn't properly recalculate when changing chromosome

it worked fine for jumping to a full chromosome, but if the destination locus was a range or gene name (e.g. EGFR) no recalculation was performed
Merge branch 'LoadFilesWithCommas'
Merge remote-tracking branch: upstream/master