Initial steps

This pull request contains three commits, in ascending usefulness (and chronological) order:

1) Move VERSION out into a constant std::string.
2) Do a little bit of light refactoring in the server to push the reading and processing of commands into separate functions.
3) Fix segmentation fault on disconnect; may cause memory leaks (which will be cleaned up when we do memory checks, I imagine), but at least it works on VS2013 now.

The end result compiles on VS2013 (and should compile elsewhere!).