Send real player entity id, implement EntityResurrectEvent, fix #1049

[SHADOWDANCH]

This pull request do such changes:

• Now server will send real entity id to player that join server instead 0, like it is works in official mojang server.
• For storing living entity potion effects now uses ConcurrentHashMap instead HashMap. Fixes ConcurrentModificationException while removing more then 1 potion effect #1049.
• Implemented firing of EntityResurrectEvent and reworked "Totem of Undying" logic to work more like in vanilla.

P.S: my english is not best :D. Feel free to say in comments if i spell something wrong.

[CLAassistant]

All committers have signed the CLA.

[Paulomart]

I would suggest splitting this PR into three separate ones. But that would be up the maintainers.

[mastercoms]

They're small enough for me not to mind this time.

[SHADOWDANCH]

I would suggest splitting this PR into three separate ones. But that would be up the maintainers.

I think about it too but for me this changes separated looks very small for pr.

[mastercoms]

I think about it too but for me this changes separated looks very small for pr.

The changes might be small. But, what if we approve one of your changes, but not the other? Then the whole PR is stalled for longer than it needs to be.

[mastercoms]

Thank you for your contribution to Glowstone!