Initial wxInfoBar implementation.

Add generic implementation, documentation and examples showing the use of the
new class in the samples.

git-svn-id: https://svn.wxwidgets.org/svn/wx/wxWidgets/trunk@62268 c3d73ce0-8a6f-49c7-b76d-6d57e0e08775

include/wx/osx/setup0.h

@@ -900,6 +900,14 @@
 // enumerated above, then this class is mostly useless too)
 #define wxUSE_IMAGLIST      1
 
+// Use wxInfoBar class.
+//
+// Default is 1.
+//
+// Recommended setting: 1 (but can be disabled without problems as nothing
+// depends on it)
+#define wxUSE_INFOBAR       1
+
 // Use wxMenu, wxMenuBar, wxMenuItem.
 //
 // Default is 1.