Improve resiliency in FUUID support

[mbax]

Two commits:

1. Updated the maven shade plugin from a snapshot version, so things actually compile these days.
2. Improved resiliency in the FUUID support. No longer tries to pass null to a nonnull constructor, instead returning null in nullable methods as appropriate. Also, saved some conversion by just directly creating factions/fplayer objects in the events.

[mbax]

Closing in favor of #8