tooltips beginning

Hey,
This is first implementation of the tooltips. I made it how you described some days ago:
TBTooltipManager - global object that check widget on pointer move event  with not empty description string and show tool tip for it.
TBWidget now contain virtual methods for get/set description string that showed in tooltips.Also I added string variable that can setted from resource (desc).
TBTooltipWindow - based on TBPopupWindow and contains TBEditFiled with readonly mode for supporting text extensions of TBEditFiled.
I didn't added special windows and tutorials in Demo, except one hint on Clear button in Text Edited window.

TODO:
- support language system. Widget can return description string from language string table if it not set in resource, for example.
- support tooltip update, for widgets that can change their description in real time.