fix multi-threading issue

[starfi5h]

Closes #109
EjectorComponent.InternalUpdate() is now multi-thread, so using non thread-safe dictionary operations may cause problems. This version uses thread-safe ConcurrentDictionary instead of Dictionary, in exchange for some performance loss.

[vrnvorona]

111 and this looks somewhat similar, maybe there is need to cooperate here? :)

[nyqeest]

@starfi5h hi can you tell me how to use this modification for RailgunRetargeting?

[starfi5h]

@nyqeest You can make your own build as Daedeross suggested, or replace the .dll with this complied file.