0.5.1 from stable with 88f1e12 and c0e4241 merged for overlay events

Updates to newest stable version of Leaflet with support for overlay events merged from main.  Specifically calvinmetcalf/Leaflet@88f1e121eea6772955fdc01629ef35ba49cd48a6 and calvinmetcalf/Leaflet@c0e4241f36dea628537e4dd5c40796fb84740b5f