This helps a lot since FileChannel is very low-level and traversing the BAMIndex involves lots of short reads.
- Fixed a deterioration in BAMIndex due to rev'ed picard (see below)
- Added unit tests for SeekableBufferedStream
- Added integrationTests for GATKBAMIndex (in PileupWalkerIntegrationTest)
- Added a runtime-test to verify that the amount read equals the amount requested.
- Added failing tests with expectedExceptions
- Used a DataProvider to make code nicer