Patch for building multi-arch RPMs with mock
Attached patch enables building for multiple architectures and multiple distros using mock (RedHat based distros).
Building RPMs for SuSe should still work via rpmbuild.
Chosen minimal version of libevent works and should be satisfied even in very old RH/SuSe distros.
Builds EL6-x86_64, Fedora 16 i386/x86_64 versions on Scientific Linux 6 (RHEL clone). Though in general it's recommended to use newer distro as build platform - build for F17 failed on SL6 due to unsupported new RPM features.