Use NMTVDISPINFO instead of TV_DISPINFO in wxMSW code.

The latest w32api 4.0.3, used by MinGW project, still didn't manage to apply a
one line fix to define TV_DISPINFO correctly, so tweak our sources to avoid
using it.

See #15537.

git-svn-id: https://svn.wxwidgets.org/svn/wx/wxWidgets/branches/WX_3_0_BRANCH@77048 c3d73ce0-8a6f-49c7-b76d-6d57e0e08775
Correct instructions for building wx applications with MSVC.

Use the correct $WXWIN/include/msvc path instead of the non-existing
$WXWIN/msvc.

Also mention that $WXWIN should actually be $(WXWIN) for MSVC.

Closes #16410.

git-svn-id: https://svn.wxwidgets.org/svn/wx/wxWidgets/branches/WX_3_0_BRANCH@77049 c3d73ce0-8a6f-49c7-b76d-6d57e0e08775