tbx: Allow indexing of empty files, do not segfault
vcfutils: bcf_gt_type should not be declared as static
vcf.[hc]: API to update FILTER column. BCF output not supported yet in this version
vcfmerge, vcfnorm: Append command and version string to VCF header
vcffilter &friends: Filtering of indels now supported. Changes in vcfcheck, plot-vcfcheck and vcfquery to reflect that. More changes and fixes to come, but this version seems stable and fully functional.
Updated tests