Defensive coding for linux updater script for consistency with alain's work on the mac script.

Should be safer if the user is installing to a path with spaces in it.

indra/viewer_components/updater/scripts/linux/update_install

 #! /bin/bash
-INSTALL_DIR=$(cd "$(dirname $0)/.." ; pwd)
-export LD_LIBRARY_PATH=$INSTALL_DIR/lib
+INSTALL_DIR=$(cd "$(dirname "$0")/.." ; pwd)
+export LD_LIBRARY_PATH="$INSTALL_DIR/lib"
 bin/linux-updater.bin --file "$1" --dest "$INSTALL_DIR" --name "Second Life Viewer 2" --stringsdir "$INSTALL_DIR/skins/default/xui/en" --stringsfile "strings.xml"
 
 if [ $? -ne 0 ]
-   then touch $2
+   then touch "$2"
 fi
 
-rm -f $1
+rm -f "$1"