Source formatting
Rename mapping.c to mapping.cc
Update travis to install libevent-dev
Require libevent 2.0 to build.
Incorporate libevent, and replace addrserver with async DNS.
Adding DBG_event level, update macro to standard format.
Restore Mud IP entry in testsuite, and fix some IP related code to be ip-agnostic.
Migrate DNS debug message to DBG_dns.
Minor fixes, display event backend on startup.
Move read_file logging to seperate debug level.
Delete all old win32/windows code. And some defunct malloc implementations.
More compile warning fixes.
Merge pull request #112 from sunyc/master

Incorporate libevent to driver, and get rid of addr server