error when compiling client library - incorrect client_settings.h

User reports compile error on OSX 10.8 with latest Xcode, with several messages similar to

client.c:1952: error: ‘cli_read_prepare_result’ undeclared here (not in a function)

Further investigation shows that incorrect include file was used (sql/client_settings.h insteaqd of correct libmysql/client_settings.h). Unfortunately, even cmake's INCLUDE_DIRECTORY(BEFORE ..) does not help here, the error happens even if -I/path/to/libmysql precedes -I/path/to/libmysql on the command line.