Initial query planner.
Merge branch 'master' of https://github.com/influxdb/influxdb into planner
Add AST string encoding, substatement extraction.
Rebuilding engine in influxql.
Refactor planner.
NOTES
Merge branch 'master' of https://github.com/influxdb/influxdb into planner
Merge pull request #1186 from influxdb/planner

Query Planner