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.

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.

Support Boolean assert()

This overload exists for Chisel 2 compatibility (Rocket uses it).

I tried to just add a single extra method ('apply(Boolean, String="")') but
Scala complained about having overloads with implicit arguments.  Instead I
just went ahead and added 4 overloads that do the same thing as the implicit
arguments, just a bit less cleanly.

Add '=/=' to bits, which does the same as '!='

It looks like this is in Chisel2 now, and some stuff in uncore is using it.
IIRC, we decided that this was the correct thing to do for some Scala style
reasons.

Meaningful error when resource copy fails.
Seems like this is exposing some deeper error with sbt and external libraries/jars.  Sometimes this error message makes sometimes the entire JVM and sbt dump with SEG fault, I don't think this is a chisel problem

Fix some nits: add that line to .gitignore that keeps coming back, do parallel testing by default

Print test stdout/stderr to console,
works for my use cases

Modify TestDriver to take resource paths instead of Files
Tested in chisel3:new_unit_tester
Tested in chisel-tutorial:chisel3prep

Fix Counter doc

Refactor tests to use stop() and assert() instead of io.error/io.done

Gate assert, printf, stop by reset
Fix testbenches that never worked
Change simulation prints to display cycle at which test was signaled to end, not when simulator stops
Better documentation for Counter

Add stop() in BasicTester as a replacement for io.done

Add support for printf and asserts, add testbench for asserts and printf

Add Option support in Bundle

Refactor test code generation, add support for additional .v files

Split internal and FIRRTL packages

More design rationale for Vec

Further testing improvements