Automatically apply and save calibration results

Using dynamic reconfigure and the serial number of the kinect save the results
of a calibration both to a yaml file and to the currently running ros instance.
This should hopefully clear up a number of annoyances during calibration.
Recursively add calibration directories if they don't exist
Add handling of and warning information about the gyro range

The gyro range is a hidden parameter that causes endless headaches for
new users until they track down the calibration wiki online.  Attempt to
shortcut this process by giving a warning and pointing towards the wiki.
Additionally, display the current value before running calibration so you
don't waste time if you've forgotten to set it, and save the parameter to
both the launch file and the calibration yaml file.
Fix the scan topic issues for now

Closes issue #69
Bug fixes
If no kinect is attached use the usb to serial converter's id instead

In case their is no kinect attached to the turtlebot (maybe their
is an Asus Xtion instead, sadly those don't appear to have serial #s)
attempt to build an id from the usb to serial converter that is
connected to /dev/ttyUSB0 in the hopes that this can uniquely identify
the turtlebot.
Bug fixes
Merge pull request #83 from kbogert/hydro-devel

Implement automatic calibration system