Map editor alpha updates

Hello and welcome our first update to the Map Editor Alpha!
We've been working hard on eliminating the most annoying and game-stopping bugs and here is a list of things we've done so far:

• You can now add and save new units
  
• Improved background image upload performance
  
• Fixed map borders not being displayed when starting a game
  
• Fixed border thickness affecting the map background when hovering over a country while saving a map
  
• A friendly message is now shown when saving the map background
  

As always, we highly appreciate your feedback and testing, so please give it a go and let us know of your discoveries.
More details on the Alpha Release can be found here