Fancy command line parsing

[Marco Gerards <metgerards@student.han.nl>]

Hi,

At the moment I am working on a patch to fix two (related) bugs.  One
bug is that tab completion does not escape spaces, the other is that
it does not take quotes into consideration.

What I did is rewriting grub_split_cmdline.  There are some helper
functions which make handling the command line very flexible.  The
patch is almost ready and I'll explain it a bit when I send it in.

This patch will affect how the scripting support can be implemented.
The parsing can be done using the helper functions I wrote so code can
be efficiently shared.

Serbinenko, are you still working on scripting support?  After sending
in my patch I will explain what the best way is to use this command
line handling for scripting support.  I hope we can talk about this so
we can add scripting support real soon.

The main reason why I send in this email is to prevent anyone from
doing redundant work, so just ignore those two bugs while I am working
on it.  And please do not work on the command line and tab completion
code, it will be changed a lot...

Thanks,
Marco