lib: add GoFile server type. Note this isn't as useful as a direct file upload because GoFile forces clients to visit a page before accessing the file, meaning e.g. the file won't embed in a chat service.

Also included is "ByteSourceUploadable" which wraps a Guava ByteSource as a jodd-http Uploadable, so that we can implement multipart-upload services as appropriate.

lib/pom.xml

@@ -27,6 +27,11 @@
             <artifactId>gson</artifactId>
             <version>2.8.6</version>
         </dependency>
+        <dependency>
+            <groupId>org.jodd</groupId>
+            <artifactId>jodd-http</artifactId>
+            <version>6.0.3</version>
+        </dependency>
         <dependency>
             <groupId>org.projectlombok</groupId>
             <artifactId>lombok</artifactId>