pumpnet: Add prinet-proxy application

Sits between the game (client) and pumpnet (server) translating
the game's native protocol to more managable http requests.

Encryption and decryption is also taken care off to remove that
burden from the server side. This makes http requests as generic as
"game version X is sending some data. here, go and figure out what
to do" on the server side.

Dockerfile

@@ -18,7 +18,8 @@ RUN apt-get update && apt-get install -y \
     libasound2-dev:i386 \
     libconfig++-dev:i386 \
     libx11-dev:i386 \
-    libcurl4-gnutls-dev:i386
+    libcurl4-gnutls-dev:i386 \
+    libsodium-dev:i386
 
 # Copy files for building to container
 RUN mkdir /pumptools