Heavy refactoring of Line (LineReader?), almost clean and with a couple of tests.
Added a dummy script to get the position of the cursor on a TTY. This was an attempt to create a wa to truly test LineReader and cursor movement by instantiating a pseudo tty and sending it the escape sequences. Can not make it work without a ridiculous amoutn of effort (and would not work outside *nix world).
 Added Should for the tests.