Fixes issue 23: fatal errors when run on merged vcf files.

Changed dot values to 0 unless the value is for GT.
Added ALT to sample info to know how many AO values there should be.
Checked number of AO values against the number of ALT values in expandSampleInfo.
Converted single dot values to multiple zeros for AO values in expandSampleInfo.
Added test 12 specific to this fix.

Files checked in: src/vcfSampleCompare.pl t/run_tests.t

Fixed a bug in genotype mode regarding handling of no calls (when the…

…re's not enough real calls to fill the sample groups to their minimum sizes.

Files checked in: src/vcfSampleCompare.pl

Changed the shebang to /usr/bin/env perl in order to support a conda …

…recipe installation.

Files checked in: src/vcfSampleCompare.pl