Holger Schemel
Summary: This patch adds support for key events for the "rewind" and "fast forward" media keys on the Amazon Fire TV remote control.
How to reproduce the problem: Run Android build of SDL2 application on the Amazon Fire TV (tested with "stick" version) and log key events.
Expected behaviour: Every key pressed on the Fire TV remote control should result in a corresponding key event (pressed/released).
Observed behaviour: Of the bottom row of buttons on the Fire TV remote control, only the "play/pause" (middle) button generates a key event, while the "rewind" (left) and "fast forward" (right) buttons to not generate any event at all.
The attached patch adds support for these two missing buttons/keys.
Note 1: Some missing definitions were added for the already existing key codes SDL_SCANCODE_APP1 and SDL_SCANCODE_APP2 (to keep up the correct order of enumerations / array positions when adding the two new key codes).
Note 2: Definitions in "scancodes_linux.h" and "scancodes_xfree86.h" (to also add support for these keys on other platforms) were added without testing. However, I was unable to find corresponding definitions for these two media keys for Windows and Mac OS X.
Note 3: I have also updated the (broken) link to the USB usage page standard PDF document (comment in "include/SDL_scancode.h").
