Fix for crashes due to OrbX TEGB scenery in XP12

This addresses a crash due a DSF parser bug, which gets triggered when OrbX's new TrueEarth Great Britain for X-Plane 12 is installed.

• Upstream fix in libacfutils: skiselkov/libacfutils@c6f11dc
• Full Changelog for OpenGPWS from v0.3: v0.3...v0.4

Important: This build has audio generation disabled and as such is only useful as a terrain database plugin. It is used by libradio, OpenWXR and other plugins which specifically interface with it. It will not provide GPWS callouts or warnings.

Universal binary version for Felis 747-200

This is only meant for the Felis 747-200. Do not use this for general purpose deployments.

Test build for Felis 747-200

Only place new interface members at the end of the structure for back…

…wards compatibility with older OpenGPWS builds.

Version with GTS820-style audio

v0.1

Removed old unused build code.