The following shell script will add all the files appear as "?" in "svn status", even if the folder or filename contains space:
svn status | grep "^\?" | sed -e 's/? *//' | sed -e 's/ /\\ /g' | xargs svn add
Be cautious that everything in your build folder will also be marked as 'A', so you might want to delete that folder before you run this script.