Bug 1109571 part 1 - Remove nsTableCaptionFrame.  r=roc
Bug 1109571 part 2 - Remove nsGkAtoms::tableCaptionFrame.  Implement nsIFrame::IsTableCaption() and use that instead.  r=roc
Bug 1109571 part 3 - Implement table caption specific code for ComputeAutoSize(), GetCorrectedParent() (for getting the style parent frame) and AccessibleType().  r=roc
Bug 1109571 part 4 - Frame construction bits to create the appropriate frame tree for table captions.  r=roc

Note that this also makes IsPositioned() table captions be abs.pos.
containers, which was broken before.
Bug 1109571 part 5 - tests.