Ok, that was a stupid question to ask, what comes from falling in panic and suspending thinking before talking :-(
Solution in case anybody else panics:
a) install the postgresql-devel package from yum
b) add the include directory '/usr/include/pgsql/server' in your IDE. In Netbeans 7.3b2 that would be in
Tools -> Options -> C/C++ -> Code Assistance -> C Compiler