Feature Parity with HTTPolice

[pevalme]

Most of the errors detected by HTTPolice can be detected by this tool by adding the proper regular expression into one of the flex sub-parsers.

[pevalme]

Commit 6f4a86456aebce656a8ebf52f166b406ee4dabac implements the needed regexp and grammars to detect almost every single error detected by HTTPolice. However, there is still some work to do here. The README includes a classification of the errors to make easier to see if an error is already implemented.