Delete queries with extra conditions should return an error

[jvshahid]

delete from foobar where foo = 'bar' should return an error instead of deleting every point in the time series, since there is no start or end time in the delete query.

[spuder]

I believed this caused a regression because it is no longer possible to delete any data the way the documentation says you should be able to.

issue #975
http://stackoverflow.com/questions/26268544/can-you-delete-data-from-influxdb

[jvshahid]

The documentation never said that you can delete points using arbitrary predicates, it clearly states that you have to use a time range.