Add debugger visualizers for Visual Studio 2012+.

Starting with 2012, Visual Studio uses a new, XML-based and actually
quite understandable format for the debug visualizers. Only basics are
included so far.

git-svn-id: https://svn.wxwidgets.org/svn/wx/wxWidgets/branches/WX_3_0_BRANCH@76704 c3d73ce0-8a6f-49c7-b76d-6d57e0e08775
Add a file with debug visualizers for MSVS 2013 and later.

For now this file contains just the visualizer for wxWindow which shows its
real (most derived) type as this is often the most useful thing you need to
know about the window.

git-svn-id: https://svn.wxwidgets.org/svn/wx/wxWidgets/branches/WX_3_0_BRANCH@76705 c3d73ce0-8a6f-49c7-b76d-6d57e0e08775
Add MSVS visualizers for wxArrayString, wxVector, wxWindowList.

Make viewing the contents of the (most common) container types easier when
debugging in MSVS 2012 or later.

Provide std::{vector,list}-like visualizers for wxVector and wxWindowList and
a special visualizer allowing to see the contents of wxArrayString in a
relatively common case when it has just or two elements.

git-svn-id: https://svn.wxwidgets.org/svn/wx/wxWidgets/branches/WX_3_0_BRANCH@76706 c3d73ce0-8a6f-49c7-b76d-6d57e0e08775
Set the 3.0.1 release date.

Update the release date in the change log and the manual.

git-svn-id: https://svn.wxwidgets.org/svn/wx/wxWidgets/branches/WX_3_0_BRANCH@76707 c3d73ce0-8a6f-49c7-b76d-6d57e0e08775
Update the release notes and the announcement for 3.0.1 release.

Document the changes in this release.

Remove the "Documentation" section from the README as it doesn't seem to be
very useful there, the link to the online documentation is the most important
thing and it's mentioned in the very beginning.

git-svn-id: https://svn.wxwidgets.org/svn/wx/wxWidgets/branches/WX_3_0_BRANCH@76708 c3d73ce0-8a6f-49c7-b76d-6d57e0e08775