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.
This was a workaround to be able to build on case-insensitive file
systems where it might get confused about <string.h> vs <String.h>.
Let's just not support building that way, so String.h can have an
objectively nicer name. :^)
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 :^)
Also run it across the whole tree to get everything using the One True Style.
We don't yet run this in an automated fashion as it's a little slow, but
there is a snippet to do so in makeall.sh.
