stop panning animation correctly, better inertia, close #2360
set the source in bindPopup(popup), close #2354
improve zoom perf by avoiding recompositing in grid layers
add DomUtil.setTransform for translate+scale ops
never stack transforms, simpler grid layer anim, ref #1705
stack transforms properly for tile layer anim, ref #1705
simpler renderer zoom anim
remove DomUtil getTranslateString/getScaleString
more consistent renderer anim calculations
cleaner ImageOverlay animation
clean up image overlay, fix setting opacity/url when not added
fix ImageOverlay on low zooms with Mercator distortion
don't disable propagation on closeButton, close #2351
do not stack transforms for real now, close #1705
a bit cleaner zoom anim logic
simpler tile bg buffer loading logic
fix box-zoom not displaying
greatly simplify zoom animation calculations - finally!!!
update changelog about 0.7.2 [skip ci]
fix year in changelog [skip ci]