- Implemented preconditions in the Lr0.applyPrecedence function.
- Added DebuggerDisplayAttribute to LrParserTable.
- Removed the preconditions from Lr0.applyPrecedence -- they're not actually needed.
- Fixed the way precedences are applied so the strategy is the same one used by 'yacc'.
- Implemented validation/precompilation of the associativity/precedence declarations.