kill() allows now paint with defined colors over rendered objects
without restore of background. It's similar to paintBackgroundBoxRel()
known from CFrameBuffer, but with possiblity to define color,
default color is 0 like before (empty background).
Items with parent bindings use the background color of its parent
as default, but can also be ignored.
This function can be useful before repaint of items and/or,
if required, to have a clean background inside item containers.
Use strictly CComponentsForm as parent parameter in constructors.
Some parts have been cleaned up (Constructors, init methodes removed)
New parameter makes it possible already add current item in constructor.
So in mostly situations is it not necessary to use explicit addCCItem(),
but addCCItem()is still valid and necessary in certain situations.
Affected are all cc-classes and their derivates.
Some classes must or can be adapted later. The function is
not currently restricted, because usage of parent parameter is not explicit
defined in constructors, see CImageInfo, here yet are used addCCItem()
methodes.
Generally this parameter is located in the constructors before bool has_shadow,
but it is not sure whether it would be better to use this parameter as the first.
That remains to be clarified.
So it's possible to use this method for all cc-items.
setCenterPos() comes now with parameter 'along_mode' (CC_ALONG_X, CC_ALONG_Y).
So it's possible to center in x or y direction. As default are
both directions predefined.
This check happens several times, therefore it is senseful, to move into own member.
Function returns false on error and is used here to show an error message if
something was wrong.
Such errors can happen on position or dimension errors e.g. out of screen or
too large display values.
Note: this is only an emergency helper for debugging on
fatal errors during developing of window stuff. Mostly errors
of this kind causing crashes and must be fixed.
