panInsideBounds: fit or center, pass options, remove boundsMinZoom

Deltas are calculated on x, y pixel coordinates separately.
Options are propagated from setMaxBounds to panBy.
No panBy loops. Fixes #1908.
test Map#setMaxBounds and Map#panInsideBounds
add chrome launcher to karma config
handle any existing tilelayers when adding attribution control
Merge pull request #2178 from snkashis/attr_handle_existing

handle any existing tilelayers when adding attribution control
Don't delay moveend event on invalidateSize

This causes unnecessary nondeterminism in the sequence of
events emitted. Instead, the caller should be responsible for
throttling, as e.g. Map#_onResize does.
remove attrib and layers control shadows for cleaner look
better clarity for attribution text
Fix tiles bluriness regression in Chrome, ref #2078
capital case for backface tile hack (just in case); add comment
use classList for class ops where available; ref #2164

makes it much faster, and also makes adding/removing classes work for
SVG elements
make className utils work for SVG elements in IE9, ref #2164
Fix build script on windows.
add Path className option
Merge pull request #2183 from danzel/build-windows

Fix build script on windows.
add leaflet-drag-target class to dragged elements, ref #2164, #1902
add multipoly openPopup, close #2046
fix maxNativeZoom on retina tile layer, close #1859, ref #1798
simplify and improve touch styles, close #1868, close #2012
Remove text shadow on mobile, ref #2012