Provide command line Arduino board selection

Support for -d <BOARD_NAME>, where <BOARD_NAME> is an
entry in the Arduino boards.txt file. Defaults to atmega328 (i.e.
Arduino Duemilanove w/ ATmega328).
Fix upload spelling error
Print arscons output on upload failure

If uploading a sketch fails for any reason (e.g. the serial port number
is invalid) then the output of the arscons command (standard output
and error) are printed out. This provides useful information for
troubleshooting.
changes for pep8 & pylint (untested because it are all changes for the Windows platform)
Fix pylint warning