Escape key superpowers
Merge pull request #146 from hammerlab/esc-key

Make the Escape key always close BioDalliance
Examine: show error if error occurs loading VCFs
Examine: Catch & display VCF parsing errors
Examine: display which VCF failed to parse
Merge pull request #147 from hammerlab/issue-121-examine_indicate-vcf-loading-error

Issue 121 examine indicate vcf loading error
Only load VCF once

code review changes
de-shadowing