Add FastCraft plugin

[BenWoodworth]

Adds my FastCraft plugin, v3.1.0, found here. SpigotMC resource is here.

[BenWoodworth]

It's probably best to wait until I add a toggle command before adding this to the server, so that players can disable it for themselves if they don't want to use it.

[xknat]

This is like, modifying stuff that you might actually want to test on a testing server, hence the test result might be different without using your plugin... making it harder to trouble shoot.
I don't see what kind of "addition" this will give xd

[BenWoodworth]

Normal crafting is still accessible through a button In FastCraft, it's completely untouched by FastCraft, so interfering with troubleshooting shouldn't be an issue. And I've actually uncovered some bugs in CraftBukkit by using FastCraft (SPIGOT-5534, SPIGOT-5642), so there could be some utility to having this on a test server.

[BenWoodworth]

Updated so that players are able to enable/disable FastCraft for themselves :)