Refactor interface integration code

Reduce document.ready code by moving functions outside and grouping
tooltip related code to a function.

Also remove window and document from wrapper anon function since
browser: true is defined in .jshintrc

Bug: 48156
Change-Id: I7228285cdcb33b915e96e7e2c59e4dbc90f5fc96

lib/jquery.ime/jquery.ime.js

@@ -760,6 +760,7 @@
 		 */
 		selectLanguage: function ( languageCode ) {
 			var ime,
+				imePref = $.ime.preferences.getIM( languageCode ),
 				language = $.ime.languages[languageCode];
 
 			if ( !language ) {
@@ -772,7 +773,8 @@
 				// Nothing to do. It is same as the current language,
 				// but check whether the input method changed.
 				if ( ime.inputmethod &&
-					ime.inputmethod.id === $.ime.preferences.getIM( languageCode )
+					ime.inputmethod.id === imePref ||
+					imePref === 'system'
 				) {
 					return false;
 				}