Added 18 utility functions.

- table.find()
- relativeToAbsolute
- absoluteToRelative
- isDXElement
- canHoldText
- isPosInElement
- isPosInElement
- isCursorOver
- dxSetParent
- dxGetParent
- dxGetPosition
- dxSetPosition
- dxGetSize
- dxSetSize
- dxSetColor
- dxSetColor
- dxSetText
- dxGetText
dxButton updated

- added text
- lighter if mouse is over it