documentation: It's U-Boot that doesn't have getopt, not Barebox ...

Commit a3ffa97f (rename U-Boot-v2 project to barebox) also changed the
U-Boot references to Barebox in the getopt description, which doesn't
make much sense.

Signed-off-by: Peter Korsgaard <jacmet@sunsite.dk>
Signed-off-by: Sascha Hauer <s.hauer@pengutronix.de>

Documentation: update reference to sandbox environment ...

examples/environment is no more. Use board/sandbox/env/ instead.

Signed-off-by: Peter Korsgaard <jacmet@sunsite.dk>
Signed-off-by: Sascha Hauer <s.hauer@pengutronix.de>

documentation updates ...

Signed-off-by: Juergen Beisert <jbe@pengutronix.de>
Signed-off-by: Sascha Hauer <s.hauer@pengutronix.de>

Cleanup colleteral damage from renaming ...

Signed-off-by: Sascha Hauer <s.hauer@pengutronix.de>

rename U-Boot-v2 project to barebox ...

This has been done with the following script:

find -path ./.git -prune -o -type f -print0 | xargs -0 -r sed -i \
	-e 's/u2boot/barebox/g' \
	-e 's/U2Boot/barebox/g' \
	-e 's/U-boot V2/barebox/g' \
	-e 's/u-boot v2/barebox/g' \
	-e 's/U-Boot V2/barebox/g' \
	-e 's/U-Boot-v2/barebox/g' \
	-e 's/U_BOOT/BAREBOX/g' \
	-e 's/UBOOT/BAREBOX/g' \
	-e 's/uboot/barebox/g' \
	-e 's/u-boot/barebox/g' \
	-e 's/u_boot/barebox/g' \
	-e 's/U-Boot/barebox/g' \
	-e 's/U-boot/barebox/g' \
	-e 's/U-BOOT/barebox/g'

find -path ./.git -prune -o \( -name "*u-boot*" -o -name "*uboot*" -o -name "*u_boot*" \) -print0 | \
	xargs -0 -r rename 's/u[-_]?boot/barebox/'

It needs some manual fixup following in the next patch

Signed-off-by: Sascha Hauer <s.hauer@pengutronix.de>