[z1985] Fix a bug in SCRIPT_COMMAND_TEMP_SUMMON_CREATURE

Now despawn-time will be treated as TEMPSUMMON_DEAD_DESPAWN as expected. Thanks to Xfurry for pointing.
Also make the DB-scripts work only with players on the map. This might affect a few rare scripts, especially related to far-teleport

Signed-off-by: Schmoozerd <schmoozerd@scriptdev2.com>

(based on commit 6ba045b)

Signed-off-by: Nighoo <nighoo@gmail.com>

(cleaned version of 49f5e90)

(based on commit [s1577] - af4e980)