Fix redlining features selection

The ModifyFeature OL control has been refactored in march:
https://github.com/openlayers/openlayers/commit/d2a32d542182fad943872928d0261671cfabf557

The changes have broken the FeatureEditing ux in CGXP (selectControl() is no more available for instance).
In addition it seems that the DeleteFeature control no more exist in OL?

This PR fixes the redlining errors reported at #484