Revision 1485

Backport from HEAD: More comfortable table view:

(ThubanBeginBusyCursor, ThubanEndBusyCursor):
        New. Wrappers around the wxWindows functions that allow us to
        make additional calls such as wxYield which gives the native
        system a chance to update the cursor correctly.
(ThubanBeginBusyCursor): Call wxSafeYield
        to make sure that we don't create reentrant possibilities with
        wxYield.