Fix spelling of "NUCLEOTIDE" in AlignmentTrack.SortOption
Add "sort" parameter to URL.

Only applies to alignment tracks, same syntax as batch command

IGV-2063
Fix javadoc reference in SearchCommand
Update VariantReviewPlugin so we can load a spec file via file-> load
Show more user-friendly error message if a genome cannot be downloaded

IGV-2067
Merge remote-tracking branch: upstream/master