* direct reference of reset is discouraged
* replaced all direct references with RegInits or removed reset
* fixed overwrites of test runs (now each in separate dir)
* added test directory to cleanFiles, will be removed on sbt clean

* implemented both hardware (runtime) logging and constructor logging
  (compile time)
* mix-in trait Logging provides methods info, warn and error (and cinfo,
  cwarn, cerror resp. for constructor logging)
* logging level is controlled by implicit Logging.Level, determined at
  each call, allows for selective logging

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