Merge branch 'refactor-syntax_unicode_button_menu' into refactor-syntax_unicode_kupdown

Conflicts:
	engine/src/button.cpp
Fix for non-OSX platforms
Merge branch 'refactor-syntax_unicode_button_menu' into refactor-syntax_unicode_kupdown
Merge branch 'refactor-syntax_unicode_button_menu' into refactor-syntax_unicode_kupdown
Merge branch 'refactor-syntax_unicode_button_menu' into refactor-syntax_unicode_kupdown
Merge branch 'refactor-syntax_unicode_kupdown' of https://github.com/runrevfraser/livecode into refactor-syntax_unicode_kupdown
Completely re-jig input on Windows to properly support Unicode input
Fix for building on non-Windows platforms
Tweaks to input handling for Windows
StringRef-based keyboard events for Linux
Add support for creating StringRefs from UTF-32
Fix major oversight in handling of key events
Unify handling of KeyPress/KeyRelease on Linux
Fix to keyboard input handling
Merge branch 'refactor-syntax_unicode_button_menu' into refactor-syntax_unicode_kupdown
Tidy up Unicode input on Mac
More tidying up of OSX input
Merge branch 'refactor-syntax_unicode_kupdown' into refactor-syntax_unicode_message_with_args

Conflicts:
	engine/src/fieldf.cpp