macOS: exec loader, harden app to /Applications

tools/osx/executable_loader.in

@@ -1,19 +1,22 @@
 #!/bin/sh
 
+# GIMP has this next line regarding raising the open-number-of-files limit:
+ulimit -n 7000
+
 cd "$(dirname "$0")" || exit 1
 
 cwd="$(pwd)"
-app="${cwd%/Contents/*}"
+app="/Applications/RawTherapee.app"
 lib="${app}/Contents/Frameworks"
 resources="${app}/Contents/Resources"
-etc="${resources}"/etc
+etc="${resources}/etc"
 export XDG_DATA_DIRS="${resources}/share"
 export DYLD_LIBRARY_PATH="${lib}"
 export GTK_PATH="${lib}/gtk-3.0/3.0.0"
 export XDG_DATA_HOME="${resources}/share"
 export GSETTINGS_SCHEMA_DIR="${resources}/share/glib-2.0/schemas"
 export GDK_PIXBUF_MODULE_FILE="${etc}/gtk-3.0/gdk-pixbuf.loaders"
-export GDK_PIXBUF_MODULEDIR="${lib}/gdk-pixbuf-2.0/2.10.0/loaders"
+export GDK_PIXBUF_MODULEDIR="${lib}"
 
 export RT_SETTINGS="${HOME}/Library/Application Support/RawTherapee/config"
 export RT_CACHE="${HOME}/Library/Application Support/RawTherapee/cache"