This patch adds a function to LineEditor that takes the current shell
buffer, searches PATH for the first program that starts with that
buffer and then compares that to any other programs starting with the
buffer to remove any mismatching characters off the end. The result is
appended to the buffer.
This may be faster with a data structure but that seems overkill.
Make LineEditor::get_line() responsible for printing the prompt. That way
we can re-prompt after clearing the screen on ^L.
This makes the Serenity Terminal feel a little bit more like home :^)
When resizing the terminal, we now clear the entire current line and reset
the shell's LineEditor input state. This makes it look and feel kinda the
same as xterm.
Fixes#286.
Hook this up in Terminal so that the '\a' character generates a beep.
Finally emit an '\a' character in the shell line editing code when
backspacing at the start of the line.
