I've added the ship production as well as corrected a few bugs related to it. You can now build more scouts or colony ships. To change the ship that you want to build, just click on the construction box in the planet UI and it'll change to the next design in the list. In the future, I plan on adding UI for selecting a ship from list, instead of looping through each ship design.
With this, I was able to colonize more planets, send population to them, and basically start feeling like a 4X game :) Tonight I'm uploading the new version, 0.5, so hopefully you all will have the new version from Desura within a few days.