return values of wxMBConv methods and tried to make them more consistent. The
only (intentional) backwards incompatible change is that cMB2WC/cWC2MB now
return the length of the converted string in outLen parameter and not length+1
Added wxMBConv::GetMBNul() and use it instead of supposing that all multibyte
strings are always terminated with a single NUL which is wrong for UTF-16/32.
Using GetMBNul(), completely rewrote cMB2WC/cWC2MB() to accept a string of the
specified length, whether it is NUL-terminated or not. This means that they
don't overwrite the provided buffer any more and convert the entire string in
all cases.
Fixed bug in wxMBConvUTF16::WC2MB() which didn't NUL-terminate the string
properlyv even if there was enough space.
git-svn-id: https://svn.wxwidgets.org/svn/wx/wxWidgets/trunk@38498 c3d73ce0-8a6f-49c7-b76d-6d57e0e08775
