String gadgets: do not disallow text and background pens being the 
same, but instead set sensible default pens.


git-svn-id: https://svn.aros.org/svn/aros/trunk/AROS@48824 fb15a70f-31f2-0310-bbcc-cdcc74a49acc
In invisible mode, set pens for use when the gadget is active as well. 
Previously, only the pens used when the gadget was inactive were set.


git-svn-id: https://svn.aros.org/svn/aros/trunk/AROS@48825 fb15a70f-31f2-0310-bbcc-cdcc74a49acc