Improved parsing performance by reducing construction overhead.
Added lower case string define.
Using new verification method to verify forced characters.
Removed old c style types used with bison.
Removed difference between known and custom headers.
Improved performance measurements.
Renamed custom_header variable name.
Reduced number of lexer states.
Refactored http_parse.
Some simplifications.
Refactored header parsing.
Several cleanups.