start to implement async 'tie' interface.
 fix api-specific select transformation.
 added instantiation of default actor-system if not passed.
 sligtly better compilation of tests.
Merge branch 'master' into async-api
 simplicify to get unsugared async interface
 initial async version compiled
 added outputPut
 start to implement async variant.
 added test-case for unsugared.
 started input channel ops.
 InputChannelOps now a common trait
 1. adopting of naive implemetations (as specified by testa) is in progress
 2. use quasi-quotations.
 test normalization after switching to async is in progress
 Added logging to channels.
 corrected write actions resubmitting.
 start from stratch
 initial structure dor continuation-based channels
 added readers
write/read once now returns Future[B]