FIX: Runs in Docker again.

Also:

- More strict `set -e`
- Global path variables.
- A few more comments
- Copyright notices

== Technically, this is a big squash merge: ===

Squashed commit of the following:

commit 5c26e223e78192ba3d788ab2c640e8c3a1c73866
Author: Daniel <daniel@harvey>
Date:   Fri Mar 27 13:11:43 2020 +0100

    MAINT: No warning if mysql_config_editor can not be found.

commit 06c3f1d25e3bd1a37942f7f0630daac82c8a7738
Author: Daniel <daniel@harvey>
Date:   Fri Mar 27 12:57:15 2020 +0100

    MAINT: Moved `set -e` more to the front.

commit 68ad8469e0dd8c5dc3c4d93f41b4902e622f579f
Author: Daniel <daniel@harvey>
Date:   Fri Mar 27 12:56:37 2020 +0100

    MAINT: Removed debugging output, added copyright lines.

commit 7ed57cdaf1d1299b5cb8d412988409410eee9b45
Author: Daniel <daniel@harvey>
Date:   Fri Mar 27 11:59:37 2020 +0100

    MAINT: moved MAINPATH definition into load_settings.sh

commit b34f82812a59e8913d40d71c3ae34f3f0106fdf2
Author: Daniel <daniel@harvey>
Date:   Fri Mar 27 10:59:57 2020 +0100

    MAINT: A bit of cleanup.

commit 4a88516991f39091edf628bcad066b6873b347c0
Author: Daniel <daniel@harvey>
Date:   Fri Mar 27 09:35:16 2020 +0100

    STY: Whitespace fixup.

commit 4724ee70
Author: Henrik tom Wörden <henrik@trineo.org>
Date:   Fri Mar 27 08:22:53 2020 +0100

    FIX: added missing env setting in applypatches

commit 1d797300
Author: Henrik tom Wörden <henrik@trineo.org>
Date:   Fri Mar 27 08:18:47 2020 +0100

    MAINT: make calling skripts more cwd independent

commit c908d69b
Author: Daniel <daniel@harvey>
Date:   Thu Mar 26 19:48:58 2020 +0100

    MAINT: Failing fast if no SQL is found.

commit 2fa7d1bb
Author: Daniel <daniel@harvey>
Date:   Thu Mar 26 19:26:57 2020 +0100

    Debug

commit a520f4a2
Author: Daniel <daniel@harvey>
Date:   Thu Mar 26 19:22:48 2020 +0100

    Debug

commit fb60953d
Author: Daniel <daniel@harvey>
Date:   Thu Mar 26 19:10:56 2020 +0100

    FIX: Loading load_settings.sh

commit d1768287
Author: Daniel <daniel@harvey>
Date:   Thu Mar 26 19:01:40 2020 +0100

    DBG .

commit b1c5d47c
Author: Daniel <daniel@harvey>
Date:   Thu Mar 26 18:55:21 2020 +0100

    FIX: Load definitions first.

commit ed5c4d9c
Author: Daniel <daniel@harvey>
Date:   Thu Mar 26 18:44:03 2020 +0100

    DBG

commit 0763ef3a
Author: Daniel <daniel@harvey>
Date:   Thu Mar 26 18:19:40 2020 +0100

    FIX: Set UTILSPATH in applyPatches.sh

commit f351aceb
Author: Daniel <daniel@harvey>
Date:   Thu Mar 26 18:08:03 2020 +0100

    FIX: More strinct error handling, message if commands are not found.

commit 0338357e
Author: Daniel <daniel@harvey>
Date:   Thu Mar 26 17:26:04 2020 +0100

    DBG .

commit 8f0545c2
Author: Daniel <daniel@harvey>
Date:   Thu Mar 26 16:46:15 2020 +0100

    MAINT: Earlier set -e, also documentation.