- Set SIZEOF_VOIDP the same way as others
 - Unindent the no Mac OS settings, to let the checker scripts find the lines
 - Removed duplicate SIZEOF_SIZE_T setting
 - Added missing value for HAVE_CHARSET_ascii

configure.cmake
 - Added HAVE_ prefix to library names, like HAVE_LIBM
 - Set HAVE_CXXABI_H if header is found, HAVE_ABI_CXA_DEMANGLE
   controls if useful
 - Set SIZEOF_VOIDP the same way as others