Show Scintilla multiple selections and multipaste features in the sample.

Add menu items to toggle multiple selections and multipaste support in wxSTC.

See #16221.

git-svn-id: https://svn.wxwidgets.org/svn/wx/wxWidgets/trunk@76461 c3d73ce0-8a6f-49c7-b76d-6d57e0e08775
Fix handling of multiple and rectangular selections in wxSTC.

Copy and paste rectangular selections in the standard format, this is
especially important under Windows where a (de facto) standard clipboard
format for such selections exists.

Also fix handling of multipaste, i.e. pasting clipboard contents into several
locations at once.

Closes #16221.

git-svn-id: https://svn.wxwidgets.org/svn/wx/wxWidgets/trunk@76462 c3d73ce0-8a6f-49c7-b76d-6d57e0e08775
Add a TODO comment to wxGTK wxToolBar::FindToolForPosition().

Replace the out of date comment saying that GTK+ doesn't have a function to do
this with a TODO comment mentioning the name of the function which should be
used here.

git-svn-id: https://svn.wxwidgets.org/svn/wx/wxWidgets/trunk@76463 c3d73ce0-8a6f-49c7-b76d-6d57e0e08775
Fix wxMSW owner drawn buttons appearance in "selected" state.

Draw the buttons (i.e. checkboxes and radio buttons) correctly when the space
key is pressed.

See #10137.

git-svn-id: https://svn.wxwidgets.org/svn/wx/wxWidgets/trunk@76464 c3d73ce0-8a6f-49c7-b76d-6d57e0e08775