Rework the /examine page for debugging VCFs, using React.js + co.

Redesigned and recombobulated the /examine page for debugging VCFs. 

![](http://cl.ly/image/1e1r3H0d0V0W/Screen%20Shot%202014-09-11%20at%201.04.12%20PM.png)

In short, a VCF is loaded into the browser, and can be filtered and ranges selected based on INFO attributes and positions in the genome. Hisograms for the various INFo attributes can be generated, and true/false pos/neg + precision/recall/f1score are shown for the selected rows. 

This uses react.js, d3.js, vcf.js, vcf.tools.js, idiogrammatik.js.

This is a provisional PR, to get this out ASAP. There are edge-cases and :bug: :snail: :bee:, as well as tests, that need accounting for. 

fixes #14 
FWIW, doing the XHRs in parallel wouldn't be too bad:

```javascript
var deferredVCF = function(vcfPath) {
  return $.post('/vcf' + vcfPath).then(function(data) {
    return vcf()
        .parseChrom(function(chr){ return 'chr' + chr; })
        .data(data)
        .data()
  });
};

$.when([deferredVCF(this.props.vcfPath), deferredVCF(this.props.truthVcfPath)])
    .done(function(records, truthRecords) {
      this.setProps({records: records, truthRecords: records,
                     chromosomes: chromosomesFrom(records),
                     attrs: _.keys(records[0].INFO)});
    }.bind(this));
```