[IMP] hw_escpos: codepage switch sequence for all encodings supported by the TM-T20 printer
[IMP] hw_proxy: better driver status reporting with hw_proxy/status, improved printing reliability
[FIX] hw_proxy: fix harmless exception on proxy restart
[IMP] point_of_sale: Realtime printer & scanner online status
[IMP] point_of_sale: refactor proxy to use event based status notifications
[FIX] point_of_sale: prevent barcode scanner connection loss
[MERGE] from trunk
[MERGE] from trunk
[MERGE] point_of_sale: hardware proxy reliability improvements