parser: Let the TIMESERIES command accept optional data-source names. These may be specified as an array of strings after the time-series identifier.
Let the network protocol and SysQL support last_update for metric stores.
Add support for fetching arbitrary objects, including attributes. That is, the backend now supports this. The functionality is not yet exposed via SysQL.
FETCH: Add parameter for fetching the main object without children. That is, exclude any attributes or child objects. Use this to simplify the TIMESERIES fetcher which no longer requires an attribute callback.
parser: Add support for metric timeseries fields.
parser: Add support for <expr> IS [NOT] TRUE / FALSE queries.
parser: Fixed setup of iterator nodes. The iterator value was supposed to be an "incomplete operator" node, that is, one of the operands should be NULL. This is actually the case now and this also means we don't have to store the operator type separately.
parser/grammar: Fix the hostname in a 'FETCH host' node.
Migrate parser from frontend/ to parser/ and to use the AST. The new parser now returns AST nodes instead of a "compiled" store lookup operator. The old parser is still in place unmodified and currently still in use.