Merge branch 'upstream'

Conflicts:
	BrailleDrivers/FreedomScientific/braille.c
	BrailleDrivers/HandyTech/braille.c
	BrailleDrivers/Papenmeier/braille.c
	BrailleDrivers/Papenmeier/config.y
	Documents/brltty.conf.in
	Programs/api_client.c
	Programs/io_misc.c
	Programs/misc.c
	Programs/scr_help.c
	Programs/usb_linux.c
	ScreenDrivers/Linux/screen.c
	configure
	configure.ac