extra memory amount allocated for string data reduced to the paragraph multiple:

extra memory amount allocated for string data reduced to the paragraph multiple:
so, in principle, it shouldn't waste any memory at all now (unless someone finds
a malloc implementation which is capable of allocation less than 16 bytes)

git-svn-id: https://svn.wxwidgets.org/svn/wx/wxWidgets/trunk@479 c3d73ce0-8a6f-49c7-b76d-6d57e0e08775