laps v0.1.0

Added

• Sub-crate laps_regex for generating state-transition table for multiple regular expressions.
• Trait and derive macro Tokenize, allow users to get a lexer by deriving Tokenize for a token kind.

Changed

• New and more intuitive syntax for macro token_ast.
• Span and InputStream now supports generic character types.
• Removed trait TokenBuilder and struct Ident.
• Removed some lexing methods in trait InputStream.