refactor(tokenizer): Use decorators for even faster parsing

[fb55]

This leads to another ~5% speed-up. Not sure if it is worth it though, as the code does get quite a bit less understandable.

[coveralls]

Pull Request Test Coverage Report for Build 1454072605

• 82 of 83 (98.8%) changed or added relevant lines in 1 file are covered.
• No unchanged relevant lines lost coverage.
• Overall coverage decreased (-0.1%) to 99.357%

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Changes Missing Coverage	Covered Lines	Changed/Added Lines	%
src/Tokenizer.ts	82	83	98.8%
<!--	Total:	82	83

Totals
Change from base Build 1449180628:	-0.1%
Covered Lines:	773
Relevant Lines:	778

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💛 - Coveralls