NewSoftSerial: fix register allocation issue.
NewSoftSerial: fix register allocation issue.

Issue/fix described in comments upstream:
  http://arduiniana.org/2011/01/newsoftserial-11-beta/

Closes #8.

Kegbot/kegbot-server,Kegbot/kegbot-server,Kegbot/kegbot-server,Kegbot/kegbot-server,Kegbot/kegbot-server