doc: more assert_eq instead of assert.
doc: more assert_eq instead of assert.

	* doc/tex2chk ($nparens): Regexp to match nested parens.
	Use to catch more opportunities to convert from assert to assert_eq.

urbiforge/urbi,aldebaran/urbi,urbiforge/urbi,urbiforge/urbi,urbiforge/urbi,aldebaran/urbi,aldebaran/urbi,urbiforge/urbi,aldebaran/urbi,urbiforge/urbi,urbiforge/urbi,urbiforge/urbi,aldebaran/urbi,aldebaran/urbi,urbiforge/urbi,aldebaran/urbi,aldebaran/urbi