sandbox: Support 'env import' and 'env export'

Adjust the code for these commands so that they work on sandbox.

Signed-off-by: Simon Glass <sjg@chromium.org>
(Adjusted to fix minor merge comflict, when applied)

Change-Id: I987dee6194cd5c83f82604caf894fc85e4eb71a8
Make 'run' use run_command_list() instead of run_command()

In the case where an environment variable spans multiple lines, we should
use run_command_list() so that all lines are executed. This shold be
backwards compatible with existing behaviour for existing scripts.

Signed-off-by: Simon Glass <sjg@chromium.org>
sandbox: Provide a build option to avoid using SDL

Some machines do not have SDL libraries installed, and it is still useful
to build sandbox without LCD/keyboard support.

Add an option for this, used as follows:

    make sandbox_config all NO_SDL=1

Signed-off-by: Simon Glass <sjg@chromium.org>
sandbox: Update and expand the README

Now that sandbox has a good base of features, the README is quite out of
date. Update it, and document the new features.

Signed-off-by: Simon Glass <sjg@chromium.org>
patman: Deal with 'git apply' failures correctly

This sort of failure is rare, but the code to deal with it is wrong.
Fix it.

Signed-off-by: Simon Glass <sjg@chromium.org>
patman: Avoid duplicate sign-offs

Keep track of all Signed-off-by tags in a commit and silently suppress any
duplicates.

Signed-off-by: Simon Glass <sjg@chromium.org>
sandbox: move source files from board/ to arch/sandbox/

Prior to commit 33a02da0, all boards must have board/${BOARD}/
or board/${VENDOR}/${BOARD}/ directory.
Now this rule is obsolete.

It looks weird that sandbox defines "vendor" and "board" just for
meeting the old U-Boot directory structure.

Signed-off-by: Masahiro Yamada <yamada.m@jp.panasonic.com>
Cc: Simon Glass <sjg@chromium.org>
sandbox: ignore sandbox.dtb

Signed-off-by: Masahiro Yamada <yamada.m@jp.panasonic.com>
Cc: Simon Glass <sjg@chromium.org>
Acked-by: Simon Glass <sjg@chromium.org>
Merge branch 'tom' of git://git.denx.de/u-boot-x86
Prepare v2014.07-rc1

Signed-off-by: Tom Rini <trini@ti.com>