#196 more move and resizing with the keyboard

[Bert Wesarg]

this patch applies after the [1781670] "instant resize keys" patch

this is a big bulk of changes and additions to my previous work of the window arrangement keys.

* in the move mode (Alt+F7), the numpad keys have the same effect like the C+A+numpad and C+A+S+numpad key bindings, respectively. The actual modifier for the C+A+S+numpad operation can be changed with the SizeMoveAltModMap option. default is shift.

* in the size mode (Alt+F8), the numpad keys are used to resize the window to the next workspace border or with the SizeMoveAltModMap to the next window border.

[Bert Wesarg]