Label style not supporting outline color

[aboudreault]

Label style doesn't support outline color (different from halo (or shadow) color). I suggest to add this style.

[Daniel Morissette]

This is related to the following MITAB bug: ​http://bugzilla.maptools.org/show_bug.cgi?id=1921

The Label Tool's "b:" parameter in Style Strings needs to be changed to specify a background box color (no longer related to Halo), and a new "o:" parameter is added to specify the outline/halo color.

Support for this needs to be implemented in ogrfeaturestyle.cpp and the following updates should be made to the Feature Style Spec doc at ​http://www.gdal.org/ogr/ogr_feature_style.html:

b: Text Box Background Color - Color of the filled box to draw behind the label, no box drawn if not set

o: Text Outline Color - Color of the text outline (halo in MapInfo terminology), no outline if not set

[aboudreault]

Patch for the label outline color support

[aboudreault]

I joined the patch with the support. Basicly, it just add the Label style type "OGRSTLabelOColor" and the associated methods.

[Daniel Morissette]

I have committed the patch adding support for outline color in r14984, and committed the updates to the ogr_feature_style.html in r14985.