Don't complete when adding . in front of an identifier

e.g., when changing foobar to foo.bar

package.json

@@ -56,7 +56,7 @@
         "c9"
     ],
     "c9plugins": {
-        "c9.ide.language": "#fad749945b",
+        "c9.ide.language": "#de3a93d63d",
         "c9.ide.language.css": "#be07d72209",
         "c9.ide.language.generic": "#4eada42071",
         "c9.ide.language.html": "#22fdc74869",