New Object for the Propeller Experiment Controller

I created an additional frequency generator object titled "EXP_FrequencyGenerator" to supplement Experimental_Functions's frequency generator methods. This object is optional, but I found this was useful in uncommon cases where multiple high frequencies needed to be generated. For lower frequencies the PWM methods in Experimental_Functions are usually adequate. The methods in the frequency generator object work identically to the methods found in Experimental_Functions. To download this object, simply download the most recent version of the Propeller Experiment Controller. For more details, see the list of changes page.