implement SCSI_START_STOP command, add debug output for unhandled CBWs
report error message when a command was not taken

adds a method to GCode object to flag when object was taken by a module
added new pin modifiers to from_string...
 ! = invert pin
 o = set pin to open drain
 ^ = set pin to pull up
 v = set pin to pull down
Set no pullup the default for open drain outputs
added repeater mode
added - to set no pullup
added @ to set repeater mode
Merge pull request #164 from wolfmanjm/feature/add-open-collector-pins

added new pin modifiers to from_string...
Pin::from_string: change nested loops for condition in case default to allow & ignore whitespace
Robot & Extruder: enable pins are no longer open drain. If you need open drain enables, put an 'o' after the pindef in your config ala Jim Morris' recent 947ae5 commit
report soft error on command unhandled

implemented suggestions from Arthur and Triffid
Merge pull request #165 from dandumit/edge

report error message when a command is not claimed
strip utf8 nbsp from comments
Module: register_for_event no longer virtual to remove an entry from the vtable and save some ram
USBSerial: allow CR to terminate lines
Don't always pull up the endstop pins. Let the user configure it with the Pin configuration (e.g. pull down instead of pull up).
change the default config to pull up end stop pins. *IF YOU WERE USING END STOPS BEFORE YOU NEED TO DO THIS*.
Merge pull request #166 from ennobler/edge

Allow endstop pull up/down configuration to be set via new config flags- do not force pull-up configuration
Merge remote-tracking branch 'fix/USBMSD' into edge
Merge branch 'edge' of git://github.com/arthurwolf/Smoothie into feature/post_play_gcode