[Documentation - HTML Legend] Added opt_flag for layer groups

[jlacroix]

In bug 1173, the support for opt_flag in layer groups.
This need to be documented

From bug 1173:
Added opt_flag support in the layer groups html template.
The opt_flag is applied on all layers in the group. If at least one layer match
the flag to show up, the group show up in the html legend.
The flags are:
1: If set, show layer even if out of scale (default: hide layers out of scale).
2: If set, show layer even if status is OFF (default: hide layers with STATUS OFF).
4: If set, show layer even if type is QUERY (default: hide layers of TYPE QUERY)
8: If set, show layer even if type is ANNOTATION (default: hide layers of TYPE
ANNOTATION) 

The default flag (if not set in the legend) is 15, sice it was the previous
behavior.

[dmorissette]

Assigned to Jeff.

[dmorissette]

Update to docs:


The flags are:
1: If set, show group even if all layers in group are out of scale (default:
hide groups out of scale).
2: If set, show group even if all layers in group have status OFF (default: hide
groups with STATUS OFF).
4: If set, show group even if all layers in group are of type QUERY (default:
hide group of TYPE QUERY)
8: If set, show group even if all layers in group are of type ANNOTATION
(default: hide groups of TYPE ANNOTATION) 

[jmckenna@…]

added opt_flag section to group block for 4.6 html legends doc, in CVS.