* some minor renames
* fix some leftover block slot references (replaced by state slot)
* fix some more uint underflows
* update epoch calculations (reward et al)
* now works past 100 epochs at least with empty blocks (very slow)
* spec updates
* make several constants uint64 to help minimize casting
* document data type woes - will have to revisit these
* change comment style on fields and constants to make room for better
comments
* add BLSVerify and BLSAddPbkeys facades to insulate spec code from
milagro
* fix proof of possession type
* drop explicitly ordered container fields from ssz - there's an issue
open to sort this out before committing it to the spec
* more work on block processing
* fix some unsigned issues
* fix ssz issue when last chunk is not full
* work around empty const seq compiler bug
* XXX -> TODO