LWG1450 Contradiction in regex_constants.

Also fixes NB GB-127 from C++11 FCD national body comments.
LWG2003 String exception inconsistency in erase.
LWG2112 User-defined classes that cannot be derived from.
LWG2132 std::function ambiguity.
LWG2182 Container::[const_]reference types are misleadingly specified.
LWG2188 Reverse iterator does not fully support targets that overload operator&.

Don't remove the parentheses around the operand of addressof.
LWG2193 Default constructors for standard library containers are explicit.

Add comma after "For the default constructor" x4.
LWG2205 Problematic postconditions of regex_match and regex_search.
LWG2213 Return value of std::regex_replace.