Add better error messages to parser.

10_compiler_i_syntax_analysis/jackcompiler/syntax/parser.py
	-Significantly improve the error messages raised by
	`GrammarRule`, by:
	-Recursively updating `GrammarRule.name` with the
	`.name` of the calling `GrammarRule`.
	-Defining a `GrammarRule.error()`, which wraps each
	exception message with useful information before sending
	it to `raise ParserException()`.