Added containsRefName to SequenceDictionary.

We'll need this, when parsing refName-based regions from the command-line.
SequenceDictionary recordNames keys should be Strings

They had been Avro Utf8 objects, which was messing up lookups into the map itself from Strings.
Added the VizReads tool to CLI.

VizReads is a tool for interactive or static visualization of aligned reads along the genome.