Implement CC Peripheral Provider API

Required for ComputerCraft 1.6 API
Modem storage and processing

Store modems based on computer ID; we don't have player name or label
available, but ID is guaranteed to be unique.
A peripheral can theoretically be attached to multiple computers, so
support that just in case.
ComputerCraft and Forge integration

Add dependency for ComputerCraft.
Use configuration file for block ID.
Register ourselves with ComputerCraft.