Linux Preview Windows + Misc Improvements

Whew... this release contains a big one.

v0.5.0 contains full FPS preview windows to the Linux side of Nicotine, largely indistinguishable from its Windows counterpart. Also in this release are numerous fixes as reported on the Nicotine Country Discord community.

Features

• Full native FPS Preview Windows on Linux
• Overhauled Linux control pane
• Linux feature parity with the Windows side

Improvements

• Full integration test suite
• Support for keybinds beyond F12
• Internationalization support for non-ANSI keyboards
• Misc optimizations

Full Changelog: v0.4.3...v0.5.0