fix slidemenu when widths are different

2.1 Issue
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if slide menu widths are different then aside will slide more, this happens because the `max` value is based only on menu width, it should vary based on menu and aside_menu

Test Case
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In kitchen sink app, `setLeftSideMenuWidth(280)` and `setRightSideMenuWidth(200)` and then slide to open aside, notice that u can slide upto 280px, even though it is only 240

Fix
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made `max` value vary based on `#menu` width or `#aside_menu` width, depending on which side is slided