View / implement intermediate values for center/rot/res
View / implement intermediate values for center/rot/res

The view now has targetCenter, targetRotation and targetResolution members.

These hold the new values given by set* methods. The actual view parameters are then changed by
calling `applyParameters_`.

ahocevar/ol3,geekdenz/ol3,adube/ol3,tschaub/ol3,ahocevar/ol3,bjornharrtell/ol3,stweil/ol3,geekdenz/openlayers,ahocevar/openlayers,geekdenz/openlayers,adube/ol3,stweil/openlayers,stweil/ol3,ahocevar/ol3,openlayers/openlayers,ahocevar/openlayers,bjornharrtell/ol3,geekdenz/ol3,stweil/openlayers,adube/ol3,oterral/ol3,geekdenz/openlayers,openlayers/openlayers,ahocevar/ol3,tschaub/ol3,geekdenz/ol3,ahocevar/openlayers,stweil/ol3,oterral/ol3,geekdenz/ol3,oterral/ol3,tschaub/ol3,bjornharrtell/ol3,stweil/ol3,openlayers/openlayers,tschaub/ol3,stweil/openlayers