refactor else if
Interface screens are now 80 columns
Some interface/keys cleanup

    * Condensed reboot code path into reset codepath
    * Reset sequence now checks for openapple or closedapple key and routes accordingly
    * Pause/Break key is now strictly emulation pause key
    * F4 is now unused
    * End key is now mapped as //e reset key (easier to hit, and less likely window manager is using it)
    * PrintScreen/SysReq key is now unused
Removed some gotos and redundant code paths
Rename protected variable to is_protected
Use zlib instead of fork/exec gzip executable

    * Now all disk images are saved gzipped
Support .do disk image extensions
Various interface/error handling improvements
separate actual inflate/deflate from wrappers
Gracefully handle zlib errors
Output the correct error message
Preferences changes

    * Deprecate "lazy" color modes
    * Allow setting speaker sound volume
    * Make Joystick code more generic (future support of touch input)
    * Deprecate setting emulator mode (//e is ascendant)
WIP : fix joystick parameters
Updated README.md