Everest Update

This update freezes the APIs for the first version of mainnet and includes numerous updates.

• avm.send now has an optional froms field to specify which address(es) to send funds from.
• nodes now track the uptime of their peers.
• auth token support was added to the http api.
• the ipc socket was changed to use raw byte streams rather than following the nanomsg protocol, due to observed message unreliability and low speeds.
• the mainnet minting function was implemented.
• gecko was renamed to avalanchego.
• fixed file descriptor leak in the plugin interface.