Update .clang-format to a Chromium-based style
Adopt base localization for the main menu xib

This mostly impacts the about box.
Remove ARC and warning setting from all configurations
Update minimum required system to 10.9 in the info plist
Update the welcome and installation experience

- Adopt base localization for the welcome window xib
- Update the GOG installer to support the new unpackgogsetup binary
- General cleanup
Delete MHKMoviePlayer

A new debug application for resources may be added in the future once the new rendering and movie infra is done.
Delete the custom exception handler. Who needs that?
Delete long dead utilities code
Update the CoreAudio PublicUtility sources to the latest version
Update libav to 10.2 and remove the 32-bit slice
Safer buffer macros for C++
New-world MHKKit

This is a big rewrite and update of MHKKit. Highlights include:

- Cleaned up code style.
- POSIX IO instead of Carbon.
- Single libav-based audio decoder for ADPCM and MP2.
- Simplified sound additions with fewer hacky-things.
- Modernized Obj-C interfaces.
Brand new mhkdump program

The old one was complicated and based on the old MHKKit.

Currently only dumps sound resources (both the original file and a decompressed version).