BindBC-HarfBuzz v0.2.0

Overview of changes leading to v0.2.0

• Add bindings for most symbols
• Add bindings for integration APIs: DirectWrite, FreeType, GDI, Uniscribe
• CoreText, GLib and GObject integrations still missing
• CoreText, Graphite2, ICU have no available bindings to hook up
• Add subset bindings and loader
• Add support for v1.7.2 (ubuntu-18.04 package)
• Update version support to v2.6.3
• Change HBSupport enum convention & version values
• Add deprecated attributes
• Convert enums to anonymous enums with alias
• Simplified converted macros
• Add tests
• Fix wrong license tag in dub.json
• Updated and clearified Readme.md