Refactor: Delete unused headers
Refactor: Remove unused math error function
Refactor: Remove cdecl function decorations
Refactor: Remove unused BADVOID configuration
Refactor: Remove unused CYGWIN configuration
Refactor: C++11 has long double
Refactor: Eliminate unused NOSIGHAND configuration
Refactor: Eliminate unused configuration USE_VARARGS
Refactor: Delete unused math error function