Description of class for lowpass/highpass filter bank.

Member variables:

Private:
	-vector of the signal

Member functions:
	-Upsample
		-Takes in vector of the signal, returns upsampled vector of y values
	-Downsample
		-Takes in vector of the signal, returns downsampled vector of y values
	-Reversal
		-Takes in a vector of the signal and returns the reversal operator applied to it.
	-Shift
		-Takes in a vector of the signal and returns the shifted signal
	-Convolve
		-Takes in two signals and returns their convolution y*x.
	-HighPass
		-Takes in a vector of the signal and returns the filtered signal by implementing the other functions in this class.
	-LowPass
		-Takes in a vector of the signal and returns the filtered signal by implementing the other functions in this class.