[CS] Don't do unnecessary hash lookups for Lexer regexes
[CS] Pre-compile all lexer regexes
[CS] Don't use a regex where a simple String#include? will do
[CS] Clean up some slightly questionable syntax
[CS] Call a buffer a spade

huh?
[CS] Avoid string allocations just for a pointer
[CS] Avoid doing multiple regex matches to find the message type

Classifies messages in constant time now