- ListItem: added attaching block paragraph/block/admonition
- List: added multiple tests in various combinations of the above e.g. nested lists, attached paragraph, attached admonition, two attached paragraphs, nested list with attached paragraph, nested list with attached multiline paragraph, attached paragraph and nested list

Important improvement: code in Coradoc::Parser::Asciidoc::Base that converts grammar rules written as ruby methods into proper parslet rules, which as it turned out was not the case previously. On top of that, it goes beyond what parslet is capable by also supporting arguments. Due to this improvement time for running all the tests came down (on tested hardware, approximately) from 50 seconds to 10 seconds (5x speedup) and time for running utils/round_trip.rb came down from 2.5 minutes to 3 seconds (50x speedup), which is also realistic input. This improvement makes it possible to iterate on grammar rules much faster, develop parsing inlines and potentially parsing input from various sources, for example test cases from asciidoc, in much more reasonable time.
- Coradoc::Parser::Asciidoc::Base was changed from a module to a class, rules previously contained there were moved to module Coradoc::Parser::Asciidoc::Text

Other improvements:
- Blocks: added missing block types: listing, open. added missing properties in literal block. (based on things noticed with utils/round_trip.rb)
- Grammar rules to be used inside of other rules e.g. line_start?, line_not_text?. Purpose of those rules is making sure rules using them are applied by parser only in places they should be applied.
- Tests for blocks, paragraph, table, two parsing bugs to be fixed
- Minor fixes in tests