[[Image(...)]] Enhancements

This fork adds the following enhancements over the ​original version:

• Better platform support: ​Mac OS X, ​Microsoft Windows, ​Android APK (beta), ​Solaris, ​FreeBSD, OpenBSD and many more
• Up to date binary packages and repositories: ​DEB (Debian/Ubuntu) / ​RPM (Fedora/CentOS), and ​many more
• Many new picture encodings: ​x264, ​VP8, ​webp, JPEG, rgb24, rgb32 and PNG image compression (all but rgb are optional, but highly recommended)
• Sound forwarding
• Support for proxy mode (many sessions on a single port)
• Support for sharing a TCP port with a web server
• Concurrent multi-client connections (experimental)
• GUI launcher
• Supports a global configuration file (/etc/xpra/xpra.conf) and per-user overrides (~/.xpra/xpra.conf)
• Zero-copy and much lower CPU overhead in network code, faster packet encoder
• System tray menu for easy disconnection, access to options and statistics
• Fast OpenGL client rendering
• Memory-mapped data transfers for local connections - extremelly fast!
• Hardware accelerated H264 encoding (NVENC)
• Hardware accelerated ​colourspace conversion
• Support for window transparency
• Better client keyboard layout support
• Handles screen update storms and fast screen refresh rates
• Support for authentication modules for securing plain TCP connections
• Encrypted connections
• Forwarding of system bell and custom application cursors
• Forwarding of application notifications (requires its own dbus daemon)
• Support for Xdummy and the RandR extension which fixes a number of otherwise unfixable display bugs (ie: #1, #2)
• Ability to disable pulseaudio and clipboard synchronization, change dpi setting, etc
• Support for shadowing existing displays
• Clean client disconnection
• Lots of small bug fixes, security fixes and portability fixes (IPv6, endianness, platforms, etc)