STYLEITEM should support line WIDTH directly (without circle symbol)

[dmorissette]

The current implementation of STYLEITEM code in mapogr.cpp still uses the old of way of rendering thick lines in Mapserver: using SIZE applied to a circular brush.

Recent releases of MapServer introduced a new STYLE WIDTH parameter that removes this requirement. We should modify the STYLEITEM code to use it instead of the old method.

[dmorissette]

Note that the "Line Thickness" paragraph of the docs will need to be updated at http://mapserver.org/input/vector/ogr.html#mapping-of-ogr-style-info-to-the-mapserver-class-members

[aboudreault]

Fixed and committed in r9191. Documentation updated in r9192.

[dmorissette]

Jeff, could you please review the doc update in r9192? I think we may need to keep both versions of the text, with a note that one applies to pre-5.6 and the other to 5.6 and up. What do you think?