Updated documentation
Following a comment from JC, with_db(PM) is converted to with_pm() to constrain the language
Processing of signals only for non-empty dfs
Corrected a bug in SignalMetadata
Updated project README.md
Corrected a bug in QueryBuilder
Introduced factory for the QueryBuilder
Corrected RQCircuitQuery for filtering events
Corrected CircuitQuery for filtering events
Corrected CircuitQuery
Corrected RQCircuitQuery and Metadata
Corrected RQCircuitQuery
Updated README.md
Corrected AssertionBuilder
Corrected event_query for PM in QueryBuilder
Corrected event_query for PM