Support for neq in query predicate
Created by: davecromberge
This is an attempt to implement support for 'not equal to' in the query predicate filtering on tag values, as described in https://github.com/dalmatinerdb/dalmatinerdb/issues/59. The parser is extended to either allow for:
tag != 'some_value or
tag NOT 'some_value'
There is related changes to be done in the index themselves to generate the correct results.