Add user invitation facilities RSM-5

Adds user invitation to teams, and framework for assigning taems
Also adds user acc. deletion.

public/js/team-editor.js

@@ -0,0 +1,6 @@
+$(function() {
+    $('#assocVacancies').multiselect({
+        disableIfEmpty: true,
+        nonSelectedText: 'Choose vacancies...'
+    });
+});