v0.3.2 release

Added

• Add all_bgs and all_thals methods to AstAccessor to enable easy access to these objects. (#61, #28)

Fixed

• Allow the spa.Actions string to be empty. (#107, #109)
• The pass keyword can now be used to create blocks in action rules that do not have any effect. (#101, #103)
• Allow comments at various places in actions rules. (#102, #104)