rolap 2.1.0

• Definition of role-playing and role dimensions (with explanatory vignette): role_playing_dimension() and get_role_playing_dimension_names() functions.
• New functions to query and rename attributes in dimensions and measures in facts: get_dimension_attribute_names(), set_dimension_attribute_names(), get_fact_measure_names() and set_fact_measure_names().
• Include detailed validation error messages.