Router unitTests has firrtl error I believe to be related to nested whens, see unitTests.Router: lines 85 and 90
some style corrections for UnitTester

The change to fix elsewhen/otherwise blew up the node count.

Fix when / elsewhen / otherwise behavior and add unit test

Accomplish this by avoiding default-null parameters on the apply methods.

updated DecoupledAdder

Calling toBits inside of flatten makes asInput/asOutput/asDirectionless fail
on SInts.  Also, the abstract type Data was already defining it to return
Seq[Bits], so this change didn't really change the API.

unable to get idle counter to work, but machinery is in place

Fixed router when using routing table entries in table with indices higher than the number of output ports

Fixed which Mem.apply used in Queue, original use was deprecated

Add a dummy chiselMain

We don't have this in Chisel3, but for compatibility with berkeley-hardfloat I
want a function header.  This lets me keep the test harness in upstream
hardfloat so I don't have to fork it for Chisel3 testing.

Router cleanup
Couple of new Test files

Added printf to show when a decoupled tester waiting for valid is doing so,  this should ultimately go away
Added init code for EnqIO and DeqIO, not sure that I agree with sense of valid use in EnqIO#enq
New and better version of Router being worked out here, first steps pass, getting closer

Fixed exception thrown when no pokes or expects in the unittester, now doesn't display table in this degenerate case
Fixed program counter size when there were exactly 2^n steps

Fixed SlowDecoupledAdder