Finished the prep-sd-image script

- Full scrub of .config/
- Inject the virtual keyboard extension
- Auto-expand the filesystem on first boot
- A more robust e2fsck routine
- Run "sync" at key points in the script
- Shrink the root filesystem as much as possible
- Don't fail if the input image file is already as small as possible.

installer/config/xinitrc

@@ -15,8 +15,7 @@ while true; do
         xrdb /home/pi/.Xresources
 
         # Start browser
-        /usr/local/bin/browser --no-first-run --disable-infobars \
-         --noerrdialogs --disable-3d-apis http://localhost/
+        /usr/local/bin/browser --no-first-run --disable-infobars --noerrdialogs --disable-3d-apis http://localhost/
     fi
 
     sleep 1