December 20 2013 - Beta-2 minor update (version 4.61)

[Zaimat]

Minor update:

* Re-enabled optimizations that were temporarily disabled this morning
* On main menu - 'Continue Game' will now be disabled if autosave is from versions 4.54-4.58 saved games (as they are incompatible and would crash otherwise)
* On new Planet List - resources will now check if they were surveyed otherwise it will show 'survey required'