TabContainer: vertical scrollbar on container (IE10)

[bill]

See some of the TabContainers in test_TabContainer.html on IE10. They get a vertical scrollbar on the TabContainer.domNode, i.e. the div containing the tabs themselves plus the ContentPanes.

It stems from the overflow-y:visible added in [27031]:

.dijitTabContainer {
    z-index: 0; /* so z-index settings below have no effect outside of the TabContainer */
    overflow-y: visible; /* prevent off-by-one-pixel errors from hiding bottom border (opposite tab labels) */
}

[bill]

In [30547]:

Make TabContainer overflow:visible rather than overflow-y:visible in 1.8 branch. It was already changed in trunk in [30152]. According to [27031] there was some browser where this caused problems with the sliding TabController, but I'm not seeing any issues. Fixes #16675 on 1.8 branch (it's already fixed on trunk), !strict. Also refs #13810, #14164.

[bill]

In [30549]:

Make TabContainer? overflow:visible rather than overflow-y:visible in 1.7 branch. It was already changed in trunk in [30152]. According to [27031] there was some browser where this caused problems with the sliding TabController?, but I'm not seeing any issues. Fixes #16675 on 1.8 branch (it's already fixed on trunk), !strict. Also refs #13810, #14164.