in some cases sfdisk reports that partitions are used and will not continue to create partition table (especially when the eMMC is already partitioned).
It's better to force sfdisk to write the partition table if we are setting up the device. 
Do not redirect output from sfdisk - just print in to stdout.

factory setup for seamless AB boot on NAND storage like kontron i.mx6ul

and function to initially flash/partition eMMC to enable seamlessly AB Updates.
Also add some helper functions.

it's not always necesarry to check md5sum.
Check on string variable "$images_md5" == "yes" and only then perform checking and using md5sum.*.txt files.

German locales have been removed so we have to use LANG=en_US.UTF8.

initial partitioning for A/B rootfs approach on emmc using ext4 filesystem partitions.
Parition layout on eMMC:
p1: bootfs
p2: rootfs_a
p3: rootfs_b
p4: userfs

- reuse function flash_ubi
- this function will only create two ubi partions (bootfs and rootfs) and AB boot is not possible
- the use of this is when big images are flashed where double copy approach is not possible anymore (storage exceeds)

* set utf-8 locale to bypass error from swupdate during installation of tar.gz archive.
* utf-8 locale should also be available on the system by setting IMAGE_LINGUAS = "de-de en-us" in yocto image.

* use $FW_DIR as source directory when flashing swu (flash_ubi_swu)
* set SWU_ARCHIVE=swupdate-img.swu as default update archive.

adapt functions to following partition setup (flash_bootloader, flash_bootloader_spl and flash_bootvars):
* /dev/mtd0 -> rootfs
* /dev/mtd1 -> U-Boot SPL
* /dev/mtd2 -> U-Boot
* /dev/mtd3 -> U-Boot Environment

* disable bootcounter in u-boot in production setup after flashing swu.
* therefore switching to a fallback system is not desired and would not work

* add function ptool flash_ubi_swu to flash A/B on nand flash

ptool burn_bootconfig: check if variable BOOT_CONFIG is non-zero before calling function burn_bootconfiguration

Add support for using command set_lan2_mac_otp to set only the second
address in OTPs. Also simplify the code a bit.

This was done using the shell-format extension in VSCode.

This script looks horrible. Let's fix and align the style at least.
This was done using the shell-format extension in VSCode.

Update productionLib.sh: allow other labels then "boot" for firmware source directory (when using local source)

productionLib.sh: Don't lock MAC OTPs after writing first MAC as we might want to write a second MAC later