basic: silence expected SAL_WARN output

These were HACK() and DbgOut() messages previously, none of these ended
up on stderr. It seems that they are more or less harmless, so as long
as nobody fixes them, silence them, so more useful warnings are not
hidden when one does e.g. xray on a drawinglayer shape.

Change-Id: I7343d93d2916d9978852418aca725d027eb09128
sw: add UI for adding a textbox for a draw shape

Change-Id: Icc4ff083431635f1769dba5907f26e7dc6b08d02
sw: add UI for removing the textbox of a draw shape

Change-Id: Ib95573228d3dc98c88cd4af19995c99433c84ae6