remove some redundant assignments
remove a potentially problematic skipping of slots in the wrong place
allow for sensor_start to fire as early as possible, but as late as necessary, via notification function, instead of using think() as workaround
let G_FindNextTarget generally skip the clientslots, and skip deactivated and not-in-use entities
add gentityCall_t struct for being passed along the functions in the chain
move the setting of creationtime into gentity initialization
refactor gentityCallAction related code out of g_spawn
fix the set entity-role of env_portal_surface
fix a typo

Conflicts:
	src/gamelogic/game/g_svcmds.c
reduce more printf usage in entity svcmds to reduce packets send over rcon
remove unused G_EntitiesFree
refactor targets to calltargets to be more specific later for a possible separation of call-targets and aim-targets
remove unused gentityCallDefinition parameter from act() to resemble use() more and simplify separation of act and use
finish the proper separation of use() and act()
allow all entities to make use of use()
add use function for doors and buttons
add use to the callaction lookup table
add a callTargetCount field and use it as callTarget availabilty test instead of the first array element
add support for fully multivalued calltargets spawning (ie. a key of datatype CALLTARGET can be set several times and will be appended to an array instead of overwriting the earlier value)