added convolutional layer draft. Needs work
fprop for convolutional layer with multiple filters
added nonlinearity to convolutional layer
added max pooling fprop
added single filter convolutional layer for simplicity. fully functional but might need to debug/check bprop/update
fixed convolutional layer boundry error
separated convolution layer into linear and non-linear. added multiple filters
removed old unit tests and made skeleton for class units
removed old files
had to remove package __init__ to make nosetests works due to nose import dropping some paths
unit tests for linear and sigmoid layer
unit tests for linear convolution layer. need to fix bprop