improve the performance when moving multiple objects with arrow keys
Some changes for more asynchronous methods, not completely finished yet
change the duplication of objects (async and link improvements)
Typo fix
inform other clients about link changes
link bugfix
links: solve the wrong rendering order which occurs when a new object is created
Add undo button
another link bugfix
Some etherpad fixes and preparations
Async fix for the exit object
Add getOverlappingObjectsAsync
add placeActiveObjectsAsync
clean up some code
Exit-Object: add possibility to create a new subroom
*added new error logger
Merge branch 'develop' of https://github.com/open-steam/webarena into develop
*changed name parent to environment
clean up some code (restored commit)
Exit-Object: add possibility to create a new subroom (restored commit)