More bugfixes

New bugfixes and changes got uploaded. Downoad the new build to get them:

- carriers got buffed and will no longer show explosions of carried units on death

- alien speeders, all extractors and interceptors got buffed in hp

- overall crystal regrowth effect of affected units is significantly better

- mining flyers should now use the closest refinery available instead of using the last known one and periodically search for a new one if their travel time is too long

- crystal field construction block in upper half of the map should now be accurate to position

- mission objective is now shown in esc-menu

- changed hp bars position of most units

- flying units get automatically targeted now

- units properly seek out flying attackers if they are able to attack them back

- unit selection is less likely to crash when using control groups during fights

- "zombie" units that refused to die should finally have the guts to properly do so

- unit creation fx volume turned down

- for now screensize is set to 1920x1080 to prevent unusable UI in some cases