Changed malloc and memset 0 to calloc, deleted unused variable "token"

Please see http://stackoverflow.com/questions/2688466/why-mallocmemset-slower-than-calloc about calloc

Than I've found an issue:
1. create server with O_THREADED or O_POLL
2. try to set_port 88
3. start listen
4. log will be spammed by 2 errors : EBADF and EDOTDOT if you are not root
I've fixed this and added simple test

Now if user have no permissions to listen to socket - he will see
>[003561] [2013-05-04 18:31:14] [ERROR listen_point.c:206] Could not bind to socket: Permission denied
[003561] [2013-05-04 18:31:14] [ERROR listen_point.c:211] Could not find any suitable address to bind to.
[003561] [2013-05-04 18:31:14] [ERROR onion.c:286] There are no available listen points

Than I've found small issue: project cannot be added as git submodule. Replacing "CMAKE_SOURCE_DIR" to "PROJECT_SOURCE_DIR" resolved this issue