call: First step towards revised -m calling (include a prior).
call -m: Prior not zero for single haploid sample
merge: Allow -i with Number=AGR tags
call -m: Support for merged raw mpileup output files,

namely for absolute QS values and missing PL values.
call -C alleles: The unseen X may not be last in merged files
call -m: Apply priors also to GT,GQ,GP
Resolved merge conflict
call -m: constrained alleles calling made aware of X allele when setting PL
stats: Resolved merge conflict
manpage: Fixed a formatting error
call -m: Add #define FLAT_PDG_FOR_MISSING
stats: Apply per-sample indel stats to indels only
Merge branch 'call-m-priors'
Updated tests