VCF Improvements and DMD Support

This release involves breaking changes to the D API.

New features since 0.13.3:

• VCF Genotype functionality along with other fixes (#116, #117)
• VCF multi-threading
• DMD support is back! #122
• Overhaul of mechanism to update htslib bindings #129, #130
• Laid groundwork for future iterators and io overhaul #128
• Logo added!

Breaking changes

• getAlignedPairs and Cigar API

What's Changed

• Vcf improvements and fixes by @charlesgregory in #125
• HtslibFile and HtslibIterator by @charlesgregory in #128
• Linker postblit fix by @charlesgregory in #123
• Dstep Bindings V2 by @charlesgregory in #129
• Update the Dstep folder after #129 by @charlesgregory in #130
• Release v0.14.0+htslib-1.13 by @charlesgregory in #131

Full Changelog: v0.13.3...v0.14.0+htslib-1.13