Revert "Remove obsolete mode_completer"

This reverts commit 95de252cef.

package.json

@@ -57,7 +57,7 @@
     "c9plugins": {
         "c9.ide.language": "#ebc064ef16",
         "c9.ide.language.css": "#be07d72209",
-        "c9.ide.language.generic": "#92210f5a48",
+        "c9.ide.language.generic": "#61a7d4f7b0",
         "c9.ide.language.html": "#22fdc74869",
         "c9.ide.language.html.diff": "#24f3608d26",
         "c9.ide.language.javascript": "#d1a479805c",

plugins/c9.static/build.js

@@ -254,6 +254,7 @@ function main(options, imports, register) {
                 "plugins/c9.ide.language/worker",
                 "plugins/c9.ide.language.generic/local_completer",
                 "plugins/c9.ide.language.generic/snippet_completer",
+                "plugins/c9.ide.language.generic/mode_completer",
                 "plugins/c9.ide.language.generic/open_files_local_completer",
                 "plugins/c9.ide.language.generic/simple/make",
                 "plugins/c9.ide.language.generic/simple/shell",