Patch Memory Leaks in Vulkan Classes

[SWinxy]

This PR fixes all memory leaks in the org.lwjgl.vulkan.awt package. This partially fixes #43, but doesn't address the OpenGL issues.

• Replaces unsafe VK10 calls with safer ones.
• SimpleDemo frees all of its memory automatically.
• JAWT objects are freed automatically.

[SWinxy]

New minor changes:

• Getter and setter for the VKData class
• Demo will destroy the surface properly when the window closes.

@httpdigest whenever you're ready 🙂

[httpdigest]

Thanks!