Batch update for August-2020

Changelog:

- Modify scripts to use bash arrays. This makes it easier to comment out
  and replace the various arguments. All the scripts were checked with
  shellcheck.

Big-Sur.md

@@ -54,14 +54,12 @@
 
   7z l SharedSupport.dmg   # test ok
 
-  mkdir stuff
+  mkdir ~/stuff
   darling-dmg SharedSupport.dmg ~/stuff
 
-  $ 7z l ~/stuff/com_apple_MobileAsset_MacSoftwareUpdate/0dc2cd535db0da2a9f559215671686ea4c055394.zip
+  $ 7z l ~/stuff/com_apple_MobileAsset_MacSoftwareUpdate/bab26be6be4f44f58c511a1482a0e87db9a89253.zip
   ...
-  2020-06-18 01:39:16 D....            0            0  AssetData/Restore
-  2020-06-18 01:38:34 .....         2848         2729  AssetData/Restore/BaseSystem.chunklist
-  2020-06-18 01:39:18 .....    740415556    735058236  AssetData/Restore/BaseSystem.dmg
+  2020-08-14 21:22:18 .....    745712482    740281200  AssetData/Restore/BaseSystem.dmg
   ```
 
   There is the required `BaseSystem.dmg` file.

CREDITS.md

@@ -81,3 +81,7 @@
 - offlinehacker - libvirt support
 
 - hellodeibu - Big Sur support
+
+- kittywhiskers - Large number of changes - thank you!
+
+- zimbatm - Thank you!

Mojave/create_iso_mojave_ng.sh

@@ -0,0 +1,38 @@
+#!/usr/bin/env bash
+
+# Create a "ISO" (DMG) image for powering offline macOS installations
+
+# Bail at first ISO creation error
+set -e
+
+display_help() {
+    echo "Usage: $(basename $0) [-h] [<path/to/install_app.app> <path/to/output_iso_file.iso>]"
+    exit 0
+}
+
+if [ "$1" == "-h" ] ; then
+    display_help
+fi
+
+if [ "$#" -eq 2 ]
+then
+    in_path=$1
+    dmg_path=$2
+elif [ "$#" -eq 0 ]
+then
+    in_path=/Applications/Install\ macOS\ Mojave.app
+    dmg_path=~/Desktop/Mojave.dmg
+    echo "Using default paths:"
+    echo "Install app: $in_path"
+    echo "Output disk: $dmg_path"
+else
+    display_help
+fi
+
+# Borrrowed from multiple internet sources
+hdiutil create -o "$dmg_path" -size 7g -layout GPTSPUD -fs HFS+J
+hdiutil attach "$dmg_path" -noverify -mountpoint /Volumes/install_build
+sudo "$in_path/Contents/Resources/createinstallmedia" --volume /Volumes/install_build --nointeraction
+
+# createinstallmedia may leave a bunch of subvolumes still mounted when it exits, so we need to use -force here.
+hdiutil detach --force "/Volumes/Install macOS Mojave"