Fix rvm_ruby_configure_flags so that it only replaces commas with spa…

…ces when they precede another option, thus allowing option values to contain commas.

Which is to say, `rvm install ruby-1.9.2-head -C --with-arch=x86_64,i386` now works.

scripts/cli

@@ -330,7 +330,7 @@ __rvm_parse_args() {
 
       -C|--configure)
         if [[ ! -z "$1" ]] ; then
-          rvm_ruby_configure_flags="$(echo $1 | tr ',' ' ')"
+          rvm_ruby_configure_flags="$(echo $1 | sed -e 's#,--# --#g')"
           shift
         else
           rvm_action="error"