Fix up premake4.lua a bit. Add snowhash project.
Fix up premake4.lua a bit. Add snowhash project.

The no-server/exceptions options are now inverted. By default, there is
no support for exceptions or the server (because I got tired of typing
--no-server --no-exceptions when regenerating makefiles). You now have
to explicitly enable either by passing --with-server or
--with-exceptions.

Currently, enabling the server will probably result in something
exploding.

nilium/snow,nilium/snow,nilium/snow