Lancet release v1.0.7

Minor release that:

1. supports a new command line parameter to request only primary alignments to be used for variant calling;
2. supports complex events: multiple consecutive snv, ins, del at a locus reported in the output VCF a a single replacement operation event;
3. includes a new parameter to control AS and XS difference when selecting read alignments;
4. implements better type support when extracting tags from sam alignments;
5. automatically turns off the active region module if MD tags are missing from the BAM file;
6. includes updated APIs: htslib v1.8 and bamtools v2.5.1;