KML line thickness should be clamped to [some very small value > 0] if 0 line thickness defined

[jng]

When a layer is exported to KML and the line/border thickness specified is 0, such lines will not be shown on Google Earth as the actual thickness value is transferred as-is.

This is not how MapGuide's image-based renderers deal with such a setting. These renderers will still draw said lines presumably with a [very small value > 0] for the line/border thickness.

The KML renderer should follow the same behaviour as the image-based renderers, namely a 0 line thickness is specified in the Layer Definition, it should be replaced with a [very small value > 0] when the KML is written.

This issue is most observable when viewing KML exported from the Fusion redline widget using default style settings. Any lines drawn won't shown because Google Earth won't draw lines/borders with 0 thickness.

[jng]

Fixed trunk (r8356) and 2.6 (r8354)