Substantially combine WiggleParser classes

IGV-1875
Fix bug where borders wouldn't always get colored when they should

This was due to using == comparison, rather than .equals
Fix bug in ToolsWiggleParser, so it no longer relies on startLocations/endLocations

These are only used in WiggleParser
Fix WiggleParser so addData works properly for all file types

IGV-1875
Tweaks to CommandExecutorTest.testSnapshotSize so it passes on test runner
Merge remote-tracking branch upstream/$:{upbranch}