libevent2 detection fails on FreeBSD 9.2
./configure --with-libevent-dir=/usr/local/lib/event2 ends with
checking for libevent directory... configure: WARNING: We found the libraries for libevent, but we could not find the C header files. You may need to install a devel package.
In freebsd libevent2 .so files are in /usr/local/lib/event2 and headers are in /usr/local/include/event2
There needs to be command line switch for setting libevent2 include path as well.