SERDES Fix

update for debug apb & regiontype in rocket-chip

comments on bootrom

Enable overriding of source ID bits in SerialAdapter

Update Switcher for rocket-chip Feb 14 2019

Add sinkId parameter for integration

Single mBus multi-port switcher support

Helps both top and testharness

Don't do anything special with simserial args

Fesvr handles this now so just pass on the plusargs and
they will be correctly ignored
Fixes #34

Fix periodchecker to not use timescale

Add README

Add prefix to vsrc, csrc and add bootrom to resources

1) Move bootrom and blackboxes to src/main/resources
2) Switch to using HasBlackBoxResource for blackboxes
3) Make build.sbt publishable by adding compile guard for rocketchip
maven dep

Add clock utilities with shells for clock mux, or, and, gater cells (copied from eagle-pll) and add withGatedClock(andReset) objects

Previous assertion was impossible to meet. This will still work assuming you don't create a full loop both on chip and off.