Adds ConnectionFactory and utils to ease the connection to the database
and execute queries.

Example usage:
Connection connection = new
ConnectionFactory("path/to/db.conf").createConnection();
QueryExecutor executor = new QueryExecutor(connection);
executor.executeQuery("SELECT ... ");
closeConnection(connection);

Change-Id: I9c00f93eed852af4720f086541aa1658e2bda7ac
Adds a model for Posts, Threads and Categories. Adds an initial
ThreadController. 

Change-Id: I8c332120adaba381f3d1d661ed3841453066e1a4