School 42 project. Implementation of a simple shell .
pipes, semicolons, escape sequences, enviroment variables, $?, ~, redirections: > >> <
Builtins: cd, pwd, echo, export, unset, env, exit.
Signals: Ctrl-C, Ctrl-\, Ctrl-D.
Parser opens quotes ' " like in bash and handles \ even in ' " different context.
Commands work with absolute and relative paths.
