Make more verbose error message, and skip getting state of layer if it is instanceof Openlayers.Layer.Vector since it has no source.
do not do anything if value is the same in TimeSlider
Merge pull request #186 from emoen/master

handle getState when layers contains Openlayers.layer.Vector, and more verbose error message.
correct opacity filter syntax
Merge pull request #187 from lbesson/patch-1

Correct MSIE opacity filter syntax
fix for gxp #189 - allow matchCase in WFS Filter