Serverino 0.4.0

[Andrea Fontana]

Hi! I've just release a new version of serverino, my pure-D 
webserver without 3rd party dependencies, super-fast to compile.

This version is featuring a basic & easy way to add routing using 
UDAs.

A big thank you to Ferhat Kurtulmuş that create a pull request 
for this :)

Just create a ready-to-go serverino using the project template:
```dub init -t serverino your_server```

And then test the new feature:
```d
import serverino;

mixin ServerinoMain;

@endpoint @route!"/hello/world" // also: @route!(request => 
request.uri == "/hello/world")
void your_request(const Request r, Output o)
{
    o ~= "Hello world!";
}

@endpoint @route!(request => r.get.has("item"))
void another_request(const Request r, Output o)
{
    o ~= "Item " ~ r.get.read("item");
}

@endpoint @priority(-1)
void this_is_a_fallback(const Request r, Output o)
{
    o ~= r.dump();
}

```

More info and docs: https://github.com/trikko/serverino