Making library non-blocking and generally awesome

 - no longer using delay() for anything; instead setting
   state to track timed maneuvers

 - updating example with a working version that uses both Sonar
   and Whiskers to detect obstacles and avoid them.
Refactoring maneuver properties into a typedef
Updating README
Updated example.
Refactoring and renaming for readability
Really updating README
Bug fixes, memory optimizing, adding debug support

 - replacing unsigned short with uint8_t
 - adding support for robot.debug(true) to enable
   command logging to Serial port
 - fixing bug in the speed calculation formula
   to make speed actually gradual.
 More debug formatting + frequency