Use variables for the rem values.

It's become obvious that these random floating points everywhere
are unwieldy. Now they're all in one place with some fairly logical
variable names which will help out in design->implementation phase.

res/css/rethemendex.sh

@@ -8,7 +8,7 @@ cd `dirname $0`
     # we used to have exclude /themes from the find at this point.
     # as themes are no longer a spurious subdirectory of css/, we don't
     # need it any more.
-    find . -iname _\*.scss | fgrep -v _components.scss | LC_ALL=C sort |
+    find . -iname _\*.scss | sort | fgrep -v _components.scss | LC_ALL=C sort |
         while read i; do
             echo "@import \"$i\";"
         done