This is a biggie...

! Replaced hand-written/optimized f'd-up lexer with an oedipus_lex generated lexer.
+ Removed RubyParser#advance. RubyParser#next_token takes care of everything now.
+ RubyParser#next_token now expects RubyLexer#next_token to return a pair (type, val).
+ Added RubyLexer #command_state and #last_state to deal with oedipus_lex differences.
+ Removed RubyLexer's @src. Now taken care of by oedipus_lex.
+ Added a bunch of RubyLexer scanning methods: beginning_of_line?, check, scan, etc.
+ Removed RubyLexer#yacc_value now that next_token returns pairs.
+ Removed RubyLexer#parse_number. Handled by oedipus_lex.
+ Added a bunch of process_* methods extracted from old yylex. process_amper, etc.
+ Finally dropped RPStringScanner's BS line number calculation (lineno). 
+ Finally dropped RPStringScanner's BS #current_line.
+ Removed lib/gauntlet_rubyparser.rb. I just don't use it anymore. Too slow.

[git-p4: depot-paths = "//src/ruby_parser/dev/": change = 9161]