Fix wxTaskBarIcon to work under all Windows versions.

Fix wxTaskBarIcon to work under all Windows versions.

When the code was compiled using a new SDK, creating wxTaskBarIcon failed
under older Windows systems because of a too big NOTIFYICONDATA size specified
by the program.

Fix this by using the fixed NOTIFYICONDATA_V2_SIZE to get old version of the
struct which nevertheless contains everything we need and even fall back to
NOTIFYICONDATA_V1_SIZE for Win9x if needed.

Closes #11886.

git-svn-id: https://svn.wxwidgets.org/svn/wx/wxWidgets/trunk@63849 c3d73ce0-8a6f-49c7-b76d-6d57e0e08775