Enhance brace pairing feature.

* latex.el: Enhance brace pairing feature.
(TeX-arg-insert-braces): Extend to be used with \bigl and its
friends.
(TeX-arg-insert-right-brace-maybe): New function.
(LaTeX-insert-left-brace): New function.
(LaTeX-insert-corresponding-right-macro-and-brace): New function.
(LaTeX-find-preceeding-left-macro-name): New function.
(LaTeX-electric-left-right-brace): New customization option.
(LaTeX-left-right-macros-association): New variable.

* style/amsmath.el ("amsmath"): Make use of the above change.
\lvert and \lVert are paired with \rvert and \rVert, respectively.
Detect a couple of hyperref rerun messages.

* tex-buf.el (TeX-LaTeX-sentinel): Add support for hyperref "Rerun
to get outlines right" messages.