TabContainer: problems w/CSS for nested TabContainers

[bill]

(As discussed /w Nikolai...)

Use of dijitAlignRight, Left, etc. in CSS files, and lack of tab-position indication on TabContainer.containerNode (the dijitTabPaneWrapper) limits customizability of tabs and creates obscure problems with nested tabs.

Clean up the CSS class names used for tabs.

[bill]

(In [14048]) Start to solve various problems w/nested tabs and ability to theme tabs.

• Put tab orientation on container node as well as on tabs (ie, labels) node, and standardize names used in the code. (ex: dijitTabContainerTop-tabs, dijitTabContainerTop-container.)
• change TabContainer?.class to reflect tabPosition (ex: dijitTabContainerTop)
• TabContainer?.domNode gets two classes (ex: dijitTabContainer and dijitTabContainerTop)

More checkins to follow. Refs #6980.

[bill]

(In [14049]) Don't use .dijitAlignLeft etc. to refer to <div> holding tabs, since it could cause obscure nesting problem (if for example, a tabPosition=left TabContainer? is in the right section of a LayoutContainer?), and also because it's hard to read such CSS. This also opens up some optimizations (".dijitTabContainer .dijitTabContainerLeft-tabs" type selectors can be simplified), but leaving that for next checkin. Refs #6980.

[bill]

(In [14053]) Get left/right TabContainers? on IE7 in RTL mode working again. There's something very strange going on w/IE that I don't fully understand but this seems to tweak it to working again. Refs #6980.

[bill]

(In [14054]) Some final code reductions for TabContainer? CSS. Fixes #6980.