Bug 834120 - Table cell accessibles not exposed for CSS table without table-row, r=tbsaunde
Bug 841789, patch 1: Rename nsIFrame::GetStyleContext() to nsIFrame::StyleContext() since it can never return null.  r=dholbert

This makes it conform to our convention that getters returning pointers
that can never be null do not begin with "Get".
Bug 841789, patch 2:  Fix callers that are going through the style context to get style structs rather than using the nsIFrame shortcuts.  r=dholbert

This is just a code simplification that I noticed while reading through
patch 1.
Bug 841789, patch 3:  Some removal of unneeded style context null-checks and comment cleanup.  r=dholbert
Bug 841896:  Rename CSSKeyframesRule.insertRule to appendRule to match spec change.

Note that this does not change the IID of nsIDOMMozCSSKeyframesRule
since neither the method signature nor semantics have changed; only the
name is different.