Substitute special characters by QGIS variables

[geraldo]

Right now we use @, ~ and ¬ to specify special characteristics like hiding a group or layer from layer switcher. We are going to remove this special characters and define this properties by QGIS project variables.

QGIS group variables:

• groups_hideintoc='["layer_name_1","layer_name_2"]' instead of @ -> "hidden"
• groups_hidelegend='["layer_name_1","layer_name_2"]' instead of ~ -> "showLegend"
• groups_wms='["layer_name_1","layer_name_2"]' instead of ¬ -> "wmsUrl", "wmsLayers", "wmsProjection"

QGIS layer variables:

• layers_hideintoc='true'|'1' instead of @ -> "hidden"
• layers_hidelegend='true'|'1' instead of ~ -> "showLegend"
• layers_wms='true'|'1' instead of ¬ -> "wmsUrl", "wmsLayers", "wmsProjection"

[geraldo]

For now I implement groups_hideintoc and layers_hideintoc this way:

• groups_hideintoc='["group_name_1","group_name_2"]' instead of @ -> "hidden"
• layers_hideintoc='["layer_name_1","layer_name_2"]' instead of @ -> "hidden"