renamed _set_greyscale_value() to _copy_greyscale_value
minor stuff
added AM_PROG_AR
renamed led_prefs_node_get_filename() to led_prefs_node_get_uri()
adapted to libniftyprefs API changes
changed url note
added LED_X,LED_Y array position definition for (x,y) tuple
added missing _frame.h, moved LED_X/Y from nifty-primitives.h to _frame.h