Expanded utils and started on connect function

Corrected a few errors in utils
Made feedback function MIMO aware (cleared TODO)
Defined tf_feedback function to act on tf objects
Added tf_step function to plot steps response of transfer function
Added input and output names to tf object - to be replaced by line
objects in future
Added name field to tf object - feels this might be unnecessary but need
some way of referencing the name of an object (since the object has most
likely been assigned a name when it was defined there must be another
way...)
Defined __pow__ function for tf object to make writing tf's using s =
tf([1 0]) possible for transfer functions with repeated factors
Added simple omega convenience wrapper under utils
Demonstrate first MatLab reference example in connect
Defined basic classes that will be used to complete connect function and
tested basic structure
Connect function needs to be expanded but a skeleton has been created