Additions to libhttpserver

Hello Sebastiano,

I've made some minor additions to libhttpserver that you are welcome to pull:

1. I've added a Makefile to the examples directory so the example programs are built (but not installed) as part of building the library and test code.

2. I've added a second example program which makes use of more of the libhttpserver API (including support for running with HTTPS).

3. I've added operator<<() to the http_request and http_response classes, so salient content from instances of these classes can be easily displayed.

I've run with these changes on Fedora Core 20 (gcc 4.8.3) and OpenSUSE 13 (gcc 4.8.1).

Regards,
    Chris Love
    cjlove@san.rr.com