Improve handling of keyboard entry using IME.

Pass the keyboard events to the IME before generating our events for them, the
IME may need them for its own use.

Closes #15384.

git-svn-id: https://svn.wxwidgets.org/svn/wx/wxWidgets/trunk@74945 c3d73ce0-8a6f-49c7-b76d-6d57e0e08775
Fix capturing non-ASCII output using wxExecute().

Explicitly use wxConvLibc with wxTextInputStream to make sure we correctly
decode non-ASCII data in the subprocess output.

This is a hack, the real solution would be to make wxTextInputStream work
properly with wxConvAuto.

See #14720.

git-svn-id: https://svn.wxwidgets.org/svn/wx/wxWidgets/trunk@74946 c3d73ce0-8a6f-49c7-b76d-6d57e0e08775