Preserve quoting for allvirtualenv command arguments

E.g allvirtualenv python -c 'import this'

Author: dbr

tests/test_allvirtualenv.sh

@@ -30,4 +30,8 @@ test_allvirtualenv_all() {
     assertTrue "Did not find test2" "allvirtualenv pwd | grep -q 'test2$'"
 }
 
+test_allvirtualenv_spaces() {
+    assertTrue "Command did not output The Zen of Python" "allvirtualenv python -c 'import this' | grep -q 'The Zen of Python'"
+}
+
 . "$test_dir/shunit2"

virtualenvwrapper.sh

@@ -1168,7 +1168,7 @@ function allvirtualenv {
         # because we don't want to trigger any hooks.
         (source "$WORKON_HOME/$d/bin/activate";
             cd "$VIRTUAL_ENV";
-            $@)
+            "$@")
         echo
     done
 }