ADC Sampling functions finished.

To start sampling: ADC_StartSampling(number of samples)
Ends with ADC_StopSampling. This function could trigger a MessageDone
signal.

The ADC sampling inserts all the sampled data into the SAMPLES_MEMORY
buffer initialized with a max size defined by MAXSAMPLES, but fills only
up to adc_number_of_samples. This buffer can be DMA'd to any internal or
external memory by the DMA controller.

To do:
Understand and create the USB communications. CPU style fifo with the
ft2232h. Really try and use DMA with this communication!