Always show hint in text entries, even when they have focus.

Always show hint in text entries, even when they have focus.

It was impossible to show the hint for the initially focused child of a dialog
before, as the hint was hidden from the very beginning. By showing it always
we avoid this problem.

We may want to add an option/flag for SetHint() to make this configurable
later if somebody really needs to show hints only for as long as the control
doesn't have focus.

git-svn-id: https://svn.wxwidgets.org/svn/wx/wxWidgets/trunk@62986 c3d73ce0-8a6f-49c7-b76d-6d57e0e08775