Fix frontend crash when rapidly aborting many active video encodings. Fixes
bug #595
foreach(dir
Bamboo
BambooPlinko
Basketball
BasketballField
Bath
Battlefield
Blizzard
Blox
Bubbleflow
Cake
Castle
Cave
Cheese
ClimbHome
Cogs
Control
CrazyMission
CTF_Blizzard
EarthRise
Eyes
Hammock
HedgeFortress
Hedgelove
Hedgewars
Hogville
Hydrant
Islands
Knockball
Lonely_Island
Mushrooms
Octorama
PirateFlag
Plane
portal
Ropes
Ruler
SB_Bones
SB_Crystal
SB_Grassy
SB_Grove
SB_Haunty
SB_Oaks
SB_Shrooms
SB_Tentacles
Sheep
ShoppaKing
Sticks
Trash
Tree
TrophyRace
)
add_subdirectory(${dir})
endforeach(dir)