IE8 fixes.

Events on VML elements actually work :)
Fix adding Vector layers during a zoom animation. Fixes #2416
enforce maxZoom before applying paddingOffset, fixes #2489
remove parens from ternary if
Merge pull request #2492 from bsstoner/bsstoner/2489

Enforce maxZoom before applying paddingOffset in Map.fitBounds, fixes #2489
Merge pull request #2418 from danzel/ie8-fixes

IE8 fixes.
Merge pull request #2419 from danzel/vector-during-zoom

Fix adding Vector layers during a zoom animation
L.LatLngBounds.extend optimization
L.LatLngBounds.extend return to Math.min/max
Manage empty L.LatLngBounds objects
simplify optimized LatLngBounds extend
fix click propagating through popup regression, close #2500
Fix for touch-sensitive browsers detecting drag on tap

Chrome 33 on Android seems to very commonly detect a 1 pixel drag movement during a standard touch tap. This fix prevents a drag from beginning until the X and Y drag offset is at least 3 pixels in total.
Update Draggable.js
Merge pull request #2503 from axefrog/master

Fix for touch-sensitive browsers detecting drag on tap