Calm before storm

Aliases rework is coming. But as it is not yet there, here is yet another release with lots of smaller changes and improvements. And of course bug fixes... I don't think there will be many new bugs this time.

Since last release, there is now one more Skript developer, @Snow-Pyon. This release mainly consists of pull requests; he has merged and tested (and sometimes fixed) most of them. So huge thanks from me to him and all pull requesters (names listed below).

• Added support for setting world to location (thanks @TheLimeGlass)
• Added inventory as an event value (event-inventory) to inventory click events (thanks @TheLimeGlass)
• Added support for setting multiple inventory slots using a single effect (thanks @TheLimeGlass)
• Added an expression which adds a timespan to given time (or current time) with better syntax (closes #1041, thanks @xXAndrew28Xx)
• Added a system for cooldowns in script-defined commands (thanks @xXAndrew28Xx)
• Added a configuration options to disable certain warnings (thanks @bi0qaw)
• Added insertion (chat feature) support for Skript's JSON chat (closes #1082)
• Added a method for addon developers to extract name from a variable (thanks @Pikachu920)
• Improved damage effect to fire an event and only apply damage if it is not cancelled (thanks @RealGatt)
• Fixed a bug that caused variables to be saved to wrong databases (thanks @bi0qaw)
• Fixed sounds on early 1.9 Spigot versions (thanks @Pikachu920)
• Fixed an issue where command declarations with many spaces would not work (closes #1086)
• Removed redundant degree override from yaw/pitch expression (thanks @xXAndrew28Xx)
• Removed unnecessary build files from repository