More flexible camera movement

Hello 

I wonder if the camera movement can more flexible like: looking around with click and drag middle mouse button, zooming in and out with scrolling up or down the mouse wheel, moving camera possition with WASD button like on other game with W key for move forward, A to left , S to backward and D to left. For moving up and down maybe either use default numpad keymap or use Q to up and E to down.

Also this not mean to replace default keymap, but a new mode for the camera that user can toggle with combined key like... alt + space maybe ?.

this new camera mode maybe can called a Fly mode.