This separates the code for each command in cbfstool. For the good and for the

This separates the code for each command in cbfstool. For the good and for the
bad: It brings a certain amount of code duplication (some of which can be
cleaned up again, or get rid of by proper refactoring).
On the other hand now there's a very simple code flow for each command, rather
than for each operation. ie.

adding a file to a cbfs means:
 - open the cbfs
 - add the file
 - close the cbfs

rather than

open the cbfs:
 - do this for add, remove, but not for create

create a new lar
 - if we don't have an open one yet

add a file:
 - if we didn't bail out before

close the file:
 - if we didn't bail out before

The short term benefit is that this fixes a problem where cbfstool was trying
to add a file if you gave a non-existing command because it bailed out on
known, not on unknown commands.

Signed-off-by: Stefan Reinauer <stepan@coresystems.de>
Acked-by: Peter Stuge <peter@stuge.se>
git-svn-id: svn://svn.coreboot.org/coreboot/trunk@4654 2b7e53f0-3cfb-0310-b3e9-8179ed1497e1