Revert "Attempt to fix issue #39; invalidateSize on resize"

It turns out there was a regression in that attempted fix which broke
existing functionality on map resizing.

This reverts commit c2857b01eb53a423e2384f1e12649721634da1ad.
Merge branch 'master' of github.com:Norkart/Leaflet-MiniMap

Silly me forgot to git pull before reverting...

Conflicts:
	src/Control.MiniMap.js