Update VE core submodule to master (1aa3143)

New changes:
b90f7f8 Localisation updates from https://translatewiki.net.
16d222c Remove .inIme state from CE Surface
abc730a build: Update jscs and use new "wikimedia" preset
457b8d9 build: Re-enable validateIndentation
6bce1d1 Localisation updates from https://translatewiki.net.
1aa3143 Cache block drop position data before setTimeout

Change-Id: I9330a67b5121f3c1c55ac4fbaf2b245d945f821f