This commit adds an endpoint to restore an entire frame from
another cluster. Multiple hosts can use this endpoint to copy
and rebalance a cluster to a new cluster.
This commit fixes the `pilosactl import` command to import data files
across an entire cluster of machines.
A `pilosactl config` command is also added to provide a default config.
This commit refactors the pilosa codebase. It makes several major
changes:
* Removes bitmap handles
* Removes dispatch/hold/transport
* Removes etcd dependency
* Adds consistent hash ring for slice placement
* Refactors parser/lexer
* Adds strong typing to PQL AST
* Flattens package hierarchy
