LibDRM KMS early work with uinput based virtual keyboard and mouse

[jsastriawan]

Please review

https://github.com/jsastriawan/MeshAgent/commit/1cf913cfd39ef3c5528224653c7740948e791c95

I got LibDRM KMS based screen scrapper working over this weekend and I have made and attempt to work on uinput based virtual keyboard and mouse.

Screen scrapper works despite occasional tearing (probably I copied the framebuffer while being updated).

Mouse movement at least is now reflected on KVM display but not yet displayed on the actual screen. If @krayon007 wants to play with this, I think this is in a much better shape that my previous code.

Oh btw, please do not setuid to other than 0 if using KMS, otherwise MeshAgent will lost DRM Master privileges and will not be able to grab the framebuffer.