* add function match_shell_handler to probe shell #! dispatcher line
* add mode field shell_handlers for generic syntax probe function
* add memfind to find keywords from buf+length
* add shell handlers for ruby, perl and python flavors, lua, haskell, ocaml
* remove perl_mode_probe
* add C++ keywords, include namespace in identifiers
* add cpp_mode_probe to detect C++ header files
* add shell handler for tcc scripts
* remove calc_mode_probe
* modify scoring between shell-script-mode and simpler sharp-mode
