v0.3 prerelease

[rrevenantt]

Current list of possible improvements for next version

• [X] workaround to use stable rust(fixes #46, fixes #34)
• [X] workaround for visitors to return data (fixes #23, fixes #22)
• [X] fixes #20
• [X] remove proc macro dependencies
• [X] CI to auto publish on new cargo.toml version
• [X] Allow storing lifetimed user data in parser(fixes #45)
• [X] limit inline bit operations to 32bits (fixes #47)
• [X] merge #38 (closes #38)
• [ ] move to once_cell completely
• [ ] rustfmt in antlr tool
• [ ] make Node and associated type in visitors
• [ ] bulk import for context extension traits
• [ ] move child methods on parserRuleContext to extention trait
• [ ] intradoc links
• [ ] move benches to repository
• [ ] LexerAtnSimulator position tracking customization
• [ ] Lexer position tracking customization
• [ ] thread local DFA(questionable because of quite slow threadlocals in rust)
• [ ] arena allocation for tree nodes/ generic(gat) trees
• [ ] use less Deref as some inheritance hack
• [ ] tree utils
• [ ] features
• [ ] stateful lexer test
• [ ] better downcasting
• [ ] options for customizing downcast bounds
• [ ] token stream rewriter
• [ ] some doctests + dummy parser for them
• [ ] actual examples
• [ ] normal visitor example/docs
• [ ] string interner test/example
• [ ] figure out base class api replacement
• [ ] rustfmt import config
• [ ] draft upstream PR
• [ ] add recursion limit
• [ ] test custom errors
• [ ] add fuzzer tests