PVPControl 1.4 for Minecraft 1.9-1.13

Dev -> Master 1.4 Hotfix 1 (#9)

* PVPControl 1.4 SNAPSHOT 1

Huge changes:
- Rebuilded modules system;
- Changed many modules;
- The biggest module - EntityDamageHandler has it's own addons system;
- Not used modules/addons for EntityDamageHandler module will be not
used and will be not affecting overall performance of plugin;
- New translations statements;
- Now you can change main prefix of the plugin;
- Fixed bug, where "THIS_COMMAND_IS_NOT_ALLOWED_DURING_PVP" translation
statement was not used.

* no changes in the settings.yml;
* build has been tested on 1.13 spigot development build;

* PVPControl 1.4 SNAPSHOT 2

Untracked some files from remote repository;

* PVPControl 1.4 SNAPSHOT 3

Remove some unused files.