* replaced unit test with much more generic property specs
* also refactored test classes into module-subpackages

* defined generic property for DecoupledDataSource:
* testing correctness (correct order + value of data), handshakes (wait
  while consumer is not ready) and repeat behavior
* running random tests over arbitrary bitwidth, size and repeat flags

* finished implementation of property based testing with random
  generators, much more thorough than the previous tests
* implemented both regular clock input and generated random clock input

* chisel3 is a little finicky with peek/poke: it seems only stuff in the
  io bundle of modules is really safe
* needed to replace peeking in the internal mems, since that seems
  to crash the LoFirrtlEvaluator
* all tests functional again

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

* separated correctness from speed tests for DWC
* correctness tests with slow queue in between and varying delays
* full speed suite tests full throughput of data stream (may not block)
* current implementation fails the latter

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

* minor bug: valid would be asserted during reset, fixed

* 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)

* separate package for SignalGenerator can be removed
* unit test included

* caused by parallel execution of suites (apparently Chisel does
  not like that)
* fixed by deactivating parallel and forked executions

* each suite now has a subdir
* each test has subdir within suite dir

* 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

* testing utility: provides fixed data via Decoupled
* configurable with/without wrap-around
* unit tests