Fix fade in RedLigning

Multiple fade and never back to normal
Make sure the initial theme is taken into account when setting the initial base layer
Merge pull request #835 from camptocamp/lastloadedtheme

Make sure the initial theme is taken into account when setting the initi...
if radius is > 50, the Streetview api doesnt return the panorama nearest to the point clicked, cf https://developers.google.com/maps/documentation/javascript/streetview
Merge pull request #836 from camptocamp/fix_streetview

fix StreetView radius
Merge pull request #834 from camptocamp/redligning-multifade

Fix fade in RedLigning
plugin PositionChooser