Dynamic Integer Sizes

[WorldofKerry]

Is your feature request related to a problem? Please describe.
Currently all python int types are converted to signed [31:0] in Verilog. That causes problems when int is larger than what can be represented in 4 bytes.

Describe the solution you'd like
For inputs and outputs:
Add a bytes-needed member to Var class, which is the max of all previous bytes-needed for inputs and outputs.

For variables local to a function, options are:

1. Add a parameter to verilogify that sets the integer size for local variables of a function.
2. Use inspect.getgeneratorlocals(generator)

Option 2 should generate more space-efficient hardware.