Add mate pair and strand information to pileup view

[hammer]

[dasmoth]

Strand information should be available in 0.13 (or a recent-ish "master" build), see https://github.com/dasmoth/dalliance/pull/72 for more information.

There is also some experimental support for linking read pairs, which can be activated if you configure a track programatically, e.g.:

    {name: 'Read pair test',
     bamURI: 'http://foo.bar/baz.bam',
     bamGroup: true}

If you get a chance to try this out, I'd be interested to hear your thoughts. Before it can be switched on by default, it probably needs some more graceful degradation in regions with very large numbers of reads.

Finally, This plugin might be of some interest.