Removed extra command 'BuildInformation' from ADAMMain
Merge pull request #266 from karenfeng/command-cleanup

Removed extra command 'BuildInformation'
.gitignore should _not_ ignore .vcf files
ADAMFlatGenotype is a smaller, flat, simpler version of a genotype schema.

Also:
1. Added support for missing genotypes in the VCFLineConverter for ADAMFlatGenotype.
2. Added a ReferenceMapping for the ADAMFlatGenotype
3. the flat genotype converter uses multiple writers for smaller output files.