Update VE core submodule to master (d418c99)

New changes:
81e2135 Remove upstreamed ve.contains function
77166d7 Update RangeFix library 0.1.0 -> 0.1.1
6fe9405 Give table overlay width so row context positions correctly in RTL
a2001e2 Fix getDirectionFromSelection to work with table selections
ca75f05 Make table inserts directional
7ce4a63 Follow-up 2075a46: Fix RTL image build by embedding after flipping
5068bcd Restore original rowspan/colspan rather than normalizing or overwriting with NaN
e1bff77 Localisation updates from https://translatewiki.net.
a92012e Use strict comparison for insertionAnnotationsChange
39f7b91 Localisation updates from https://translatewiki.net.
b5e1130 Localisation updates from https://translatewiki.net.
c577aeb Initialize mobile context as visible

Change-Id: I113250f8caec07f9a7e59116417eb582ea0e7ae5