Merge branch 'spinctrl-value'

Consistently return minimum value from wxSpinCtrl with invalid text
value.

See https://github.com/wxWidgets/wxWidgets/pull/2345

docs/changes.txt

@@ -114,6 +114,12 @@ Changes in behaviour not resulting in compilation errors
 
 - wxChoice::GetString() now consistently asserts when passed an invalid index.
 
+- wxSpinCtrlDouble now always resets its value to GetMin() if an invalid text
+  string is passed to its SetValue(wxString) overload after its creation.
+
+- wxSpinCtrl::SetValue(wxString) overload doesn't generate any events with
+  wxMSW, which was already the documented behaviour.
+
 
 Changes in behaviour which may result in build errors
 -----------------------------------------------------