Moving all files to main folder.
Using Gradle to define, manage dependecies and build the project.
Upgraded Gradle wrapper.

L2J/L2J_Server@2f3dca83e5317b7471ac1bf472067e9ad1a85003

	* Unhardcoded some HTMLs.
	* Renamed `INSTNACEID` to `TEMPLATE_ID`.
	* Fixed missuse of template ID and instance ID in multiple instances.
	* Fixed Ranku, Demon Prince, Urban Area, Monastery Of Silence, Library Of Sages.

Reported by: !FinalDestination, !CostyKiller, JOJO

	* Also including new admin command !//setinvis which will toggle visibility/invisibility of your target.

	* Fixed some messy code.

* Reviewed by: malyelfik, Zoey76, !UnAfraid, Adry_85