Using attribute mask and assuming three genotype levels.
Parallel genotype level updates by attribute rather than by instance.
Changed monomorphic detection to use PLINK-style MAF filtering < 0.000001.
* Command line flags/options for:
	--fast-gwas
	--monomorphic-filter
* Fixed seg fault when detecting unsupported file extentions/types.
Removed initialization of level counts. Update does this. More output for --convert mode.