migrate-sles-to-sles4sap-15.1.2-160000.1.1

- Add %changelog to spec
- Adapt script for SLE16
- Add migrate-sles-to-sles4sap for 16.0
  (jsc#PED-13724)

- Migrate Script SLES15-to-SLES4SAP misses wget
  (bsc#1205281)
  Add missed dependencies

- migrate-sles-to-sles4sap package has dependency perl-XML-Twig
  that is not installed
  (bsc#1189481)
  Add missed dependency

- (bsc#1187433) - migrating SLES to SLES for SAP with SMT server fails
  (bsc#1171033) - migrate-sles-to-sles4sap: smt url for clientSetup4SMT.sh is wrong
  Fix setup scripts url
- Fix pattern to find release packages

- fixed bsc#1112548 - rollback for failed migration
- Removed several hacks that aren't necessary anymore, due to
  changes in SUSEConnect
- Bootloader change isn't necessary anymore as SLES will always be
  shown in GRUB2 regardless if SLES or SLES for SAP
- removed hardcoded version dependencies to make the script version
  independent
- added rollback in case of failed migration
- added additional runtime warnings and infos for user
- restructured code for cleaner readability
- fixed ShellCheck issues
- changed parsing for variables like VERSION and CPE from
  /etc/os-release to /etc/products.d/baseproduct, as
  /etc/os-release doesn't differ on SLES and SLES for SAP
- script now checks the SSL certificate of SMT and RMT servers
- added user input to allow self-signed SSL certificates on SMT and
  RMT servers
- fixed RMT registration
- added Malte Kraus as author, due to his input on the security
  checks

- bsc#1112548 - in case registration fails roll back to SLES
  * sles-release is removed before trying to register the system.
    In case the registration fails the system does end up without
    release files and can't be registered anymore.
  * now backing up sles-release RPM before de-registering SLES
  * installing sles-release RPM after failed registration to have
    a system that can still use SUSEConnect for registration.
- fix warnings by ShellCheck regarding code style
- be more verbose regarding error messages

- bsc#1116214: submission to SLES 15 SP1

- Update for SLE_SAP 15 SP1

- Adjusted the script to work with the new SLE-15 RMT service,
  instead of the SLE-12 SMT.

- Updated for SLE-15 migration. Included the behavior to register
  all the default modules and products of SLES for SAP.