Revert "Revert first, fix later: multi-line call tooltips"

package.json

@@ -55,7 +55,7 @@
         "c9"
     ],
     "c9plugins": {
-        "c9.ide.language": "#6bf8635993",
+        "c9.ide.language": "#238788394c",
         "c9.ide.language.css": "#a649f2a710",
         "c9.ide.language.generic": "#77d43cfaf0",
         "c9.ide.language.html": "#0f4078c187",
@@ -63,7 +63,7 @@
         "c9.ide.language.javascript": "#2b77bdb96a",
         "c9.ide.language.javascript.immediate": "#0535804ada",
         "c9.ide.language.javascript.eslint": "#3ec4557969",
-        "c9.ide.language.javascript.tern": "#8233331bc9",
+        "c9.ide.language.javascript.tern": "#84c0afcc50",
         "c9.ide.language.javascript.infer": "#8478e3c702",
         "c9.ide.language.jsonalyzer": "#45453961d9",
         "c9.ide.collab": "#30efed939e",
@@ -90,6 +90,7 @@
         "c9.ide.imgeditor": "#612e75ef4f",
         "c9.ide.immediate": "#a962119bec",
         "c9.ide.installer": "#0fde9f0067",
+        "c9.ide.language.python": "#undefined",
         "c9.ide.mount": "#b9a5a2d45c",
         "c9.ide.navigate": "#38ae100ea1",
         "c9.ide.newresource": "#981a408a7b",

plugins/c9.ide.panels/panel.js

@@ -243,7 +243,7 @@ define(function(require, module, exports) {
                     else
                         panels.deactivate(plugin.name);
                     
-                    if (tabs.focussedTab && !panels.showing)
+                    if (tabs.focussedTab && tabs.focussedTab.editor && !panels.showing)
                         tabs.focussedTab.editor.focus();
                 }
             }