libevent upgrades

[Blair Zajac]

Brett,

When you bump a libevent version, please bump the revision number on all 
packages that depend upon it since they will need to be recompiled.

Here's memcached after running with the libevent upgrade:

$ /opt/local/bin/memcached --help
dyld: Library not loaded: /Users/blair/my-macports/lib/libevent-1.3e.1.dylib
   Referenced from: /opt/local/bin/memcached
   Reason: image not found
Trace/BPT trap

I've bumped the revision number of memcached in r36063 to force a recompile.

Regards,
Blair