Splitview fixes

2.1 Issue
-
aside menu width incorrect in splitview

Test Case
-
set $.ui.splitview = true, check on ipad portrait, notice that aside width is not correctly set.

Fix
-
added `splitview` class for `#aside_menu`, so that `#aside_menu` width is applied only when splitview is present.

`window.innerWidth >= $.ui.handheldMinWidth` instead of `window.innerWidth > $.ui.handheldMinWidth`

slidemenu fixes when only one menu is present