influxql: invalid duration literals parsed successfully and treated as 0s

[mark-rushakoff]

With the NOAA data:

> select * from h2o_feet where time > now() - 10000d limit 3
name: h2o_feet
time                level description    location     water_level
----                -----------------    --------     -----------
1439856000000000000 between 6 and 9 feet coyote_creek 8.12
1439856000000000000 below 3 feet         santa_monica 2.064
1439856360000000000 between 6 and 9 feet coyote_creek 8.005

> select * from h2o_feet where time > now() - 10000w limit 3
name: h2o_feet
time                level description    location     water_level
----                -----------------    --------     -----------
1439856000000000000 between 6 and 9 feet coyote_creek 8.12
1439856000000000000 below 3 feet         santa_monica 2.064
1439856360000000000 between 6 and 9 feet coyote_creek 8.005

> select * from h2o_feet where time > now() - 10000y limit 3
> select * from h2o_feet where time > now() - 10000asdf limit 3
> select * from h2o_feet where time > now() - asdf limit 3
ERR: invalid operation: time and *influxql.BinaryExpr are not compatible

The y suffix is something that people are likely to try, even though it's not a supported unit.

Both the y and asdf (and any other suffix that isn't a valid unit) show up in the query log as parsed as 0s.