Automated build publication to CurseForge

With this feature you can automatically upload builds to CurseForge.

@sinkillerj you can do this by:
* Generate an API token by going to http://minecraft.curseforge.com/account/api-tokens
* Copy the token
* Open up the command line and enter gradlew -PapiKey=thekeyyougenerated curse
* There should now be a new archive on the CurseForge page.

Sorry for the instructions, just wanted to make sure you know how to use this if you decide to merge this :)