binding => topBinding so that partial Bundles work and undefined Bundle members properly forward to DontCareBinding

This shows errors comparing literals

Provide direct conversion from ChiselIR to FIRRTL.
Provide Driver support for dumping ProtoBuf.

Resolves #841

Signed-off-by: Schuyler Eldridge <schuyler.eldridge@ibm.com>

Documentation for example had parameters in wrong order, and was missing @param. Additionally, it was lacking a module wrapper. This has been corrected.

Add chisel3.experimental.IO for programmatic port creation in Raw and
MultiIOModules. suggestName is required to name ports that cannot be
named by reflection. Two ports cannot be given the same name.