scrcpy v1.4

Changes since v1.3:

• Send raw key events for letters to use keyboard in games (#87)
• Add feature to push file to /sdcard/ via drag & drop (#226)
• Add command-line option to start in fullscreen (#252)
• Improve error message on missing adb (#236, #254)
• Keep the console open on error on Windows (#261)
• Fix possible session crash on close (#52, #182)
• Return non-zero value on connection loss (#204)
• Avoid additional buffer copy in userspace on the server
• Update platform-tools to 28.0.1 (adb) included in Windows releases (#224)
• Update FFmpeg to 4.0.2 included in Windows releases