Remove "stash=true" event component from stash event

Related to
https://github.com/clintbellanger/flare-engine/issues/583
Replace "type=teleport" by "type=custom" in maps

The flare-engine complains about any events, which have no special
action attached to them, but are different from 'custom'.
See commit 1593b5a93ae2dec2e66195481177b8d6f35a7030 in flare-engine
for detail.

This commit replaces any teleport events in the maps by custom events.
Merge pull request #307 from stefanbeller/stashevent

Remove "stash=true" event component from stash event
Merge pull request #308 from stefanbeller/removeteleportevents

Replace "type=teleport" by "type=custom" in maps
Replace event types "custom" and "run_once" by "on_trigger"

The former "run_once" events have an additional "repeat=false" event
component.
Replace "stash" event by "on_trigger" event, add "stash=true" again
spawn maps events type changed to "on_load" instead of "custom"
Replace "run_always" events by "on_trigger" events
Fix soundfx in brothers lair ice hall

Renamed event component "sound" to "soundfx"
Game part for https://github.com/clintbellanger/flare-engine/pull/625
Merge pull request #310 from stefanbeller/events

Reorganize event types.
This implements the engine changes as of clintbellanger/flare-engine#633
Merge pull request #311 from igorko/master

Data for https://github.com/clintbellanger/flare-engine/pull/625
Merge pull request #1 from clintbellanger/master

take latest changes from main project