Fix untargetable barrel in Soviet 01
Update CHANGELOG
Only play movies in Allies 01 and Soviet 01 Classic if there's one client
add classic left-click orders
improve the classic mouse behaivor

- don't require to deselect units to change selection
- fix issue with broken building placement on right-click orders
- don't select enemy units when left-click attacking
- build palette won't interfere with unit orders anymore
let Chronotank/Minelayer accept left-click-orders
pull mouse button preference from global property