Update AppRun for AppImage

This is a short-term fix for an issue leading to warning messages.
The list of such messages appearing under certain conditions is this:

````
magick: UnableToOpenConfigureFile `magic.xml' @ warning/configure.c/GetConfigureOptions/714.
magick: UnableToOpenConfigureFile `coder.xml' @ warning/configure.c/GetConfigureOptions/714.
magick: UnableToOpenConfigureFile `colors.xml' @ warning/configure.c/GetConfigureOptions/714.
magick: UnableToOpenConfigureFile `configure.xml' @ warning/configure.c/GetConfigureOptions/714.
magick: UnableToOpenConfigureFile `delegates.xml' @ warning/configure.c/GetConfigureOptions/714.
magick: UnableToOpenConfigureFile `type.xml' @ warning/configure.c/GetConfigureOptions/714.
magick: UnableToOpenConfigureFile `mime.xml' @ warning/configure.c/GetConfigureOptions/714.
magick: UnableToOpenConfigureFile `thresholds.xml' @ warning/configure.c/GetConfigureOptions/714.
````

Note, I've been working on an improved and extended AppRun script for the AppImage, which I've not yet completed due to some heavy time restrictions. Hopefully I can complete this soon...
diff --git a/AppRun b/AppRun
index 16d9403..bfcca50 100644
--- a/AppRun
+++ b/AppRun
@@ -7,9 +7,12 @@
 
 HERE="$(dirname "$(readlink -f "${0}")")"
 
-export MAGICK_HOME="$HERE/usr" # http://www.imagemagick.org/QuickStart.txt
-export MAGICK_CONFIGURE_PATH=$(readlink -f "$HERE/usr/lib/ImageMagick-*/config-*/") # Undocumented?
- 
+export MAGICK_HOME="$HERE/usr:$MAGICK_HOME" # http://www.imagemagick.org/QuickStart.txt
+export MAGICK_CONFIGURE_PATH=$(readlink -f "$HERE/usr/lib/ImageMagick-7.0.7/config-Q16HDRI"):$(readlink -f "$HERE/usr/share/ImageMagick-7"):$(readlink -f "$HERE/usr/etc/ImageMagick-7"):$MAGICK_CONFIGURE_PATH #Wildcards don't work
+
+export LD_LIBRARY_PATH=$(readlink -f "$HERE/usr/lib"):$LD_LIBRARY_PATH
+export LD_LIBRARY_PATH=${HERE}/usr/lib/ImageMagick-7.0.7/modules-Q16HDRI/coders:$LD_LIBRARY_PATH
+
 if [ "$1" == "man" ] ; then
   export MANPATH="$HERE/usr/share/man:$MANPATH" ; exec "$@" ; exit $?
 elif [ "$1" == "info" ] ; then