Center text in Sashimi arcs
Have cufflinks plugin give better default output track names

IGV-1908
Use log instead of System.out
Properly increment temporary rectangle when deciding whether to render sample or genotype

Mistakenly we only incremented if the genotype rectangle was shown, which meant that if the first rectangle wasn't shown none of the later ones would be.

IGV-1952
Modify test setup so oldOut is initialized to System.out

Before we were hitting NPEs when accessing it because we were accidentally setting it to null
Improve handling of chromosome change events

Fix IGV-1953 by posting a ZoomCause event as well when searching for just a chromosome
Minor cleanup of BedToPeaks
Use IGVSeekableHttpStream for byte-range test to deal with proxies properly.