Fixes for 0.7.9.1 release (=> 0.7.9.2)
- Avoid calling mergeVCFfiles when outputing variants to standard out
- Clean up recent isValidVcfLine addition to be a non-class function and use correct local name (`line`)
Merge pull request #22 from chapmanb/master

Fixes for 0.7.9.1 release (=> 0.7.9.2)