* new full speed test suite failed: output may not block
* fixed by adding new special case
* achieves full speed & correctness now

* DWC only worked correctly at full speed
* delays caused lost nibbles, fixed now
* added secondary test harness to test against a slow receiver

* previous implementation was not capable of handling a continuous
  stream of data (continuity must be preserved to avoid congestion)
* new implementation fixes this and several other minor issues
* better unit test: now using inverted pairs of DWCs
* makes testing code much simpler and data/waves easier to check
* added additional tests to specify the required timing behavior
  (i.e., preserving continuous data streams)

* upsizing mode (inWidth < outWidth) implemented
* added unit test support for upsizing

* basic Decoupled-based data width converter
* currently only downsizing implemented with endianess selector
* works, but performance is lackluster yet
* unit tests cover several interesting combinations in both endianesses