single full-width edit box. multiedit()'s extra functionality has been
superseded by the "columns" mechanism, and it didn't allow an edit box to
be created with no label.
Also add no-label capability to a couple of other controls.
[originally from svn r5626]
long last to move all the Windows-specific source files down into a
`windows' subdirectory. Only platform-specific files remain at the
top level. With any luck this will act as a hint to anyone still
contemplating sending us a Windows-centric patch...
[originally from svn r4792]