update metrics_idx when updating meta data
add method back since it is used in tests
initial support for data retention

This commit adds support for configuring numeric data retention at the tenant
level.
Initial support for an ANTLR-base Influx query parser

The initial grammar only understands these queries:
- list series
- select * from my_series
- select * from "312 _ strange\" name"

Two tests check queries which we expect can be parsed and cannot.

The ANTLR Maven plugin builds the lexer and parser during the
generate-sources phase.
Improved syntax tests

* Filter out commented lines in test samples files
* Better reports in case of failure
Influx grammar enhancement

* column definition
* column definition list
* aggregation functions
* aliased columns and series
Influx grammar enhancement

* LIMIT clause
Influx grammar enhancement

* WHERE clause (without regular expression operators)
Influx grammar enhancement

* Group By clause
Added a query type detector

Also, some test code refactoring
Influx grammar enhancement

* Support date, datetime and long datetime expressions
Influx grammar enhancement

* Functions may have multiple arguments
* Function args may be names, numbers, or strings
Influx grammar fix: group by and where may appear in any order
Added log4j config file for tests
Naming changes in test code
Import changes
Revert POM changes
Make diff against master more readable
Added SelectQueryDefinitionsPhase.

This class is a parse tree listener which will define select queries entities: columns, from clause, ... etc.

This commit adds support for column definitions (with a test case).
Rearrange code in new packages