Update VE core submodule to master (97a5007)

New changes:
9e2238b Add special case for up/down arrow key on focusable node
30f0329 Fix for cursoring into focusable nodes with up/down
6c8da6a Fix spacing inside fragment inspector
3114f74 Remove Firefox listnode hack
e7d98b7 Fix calculation of affectedRange in transaction processor
c6d7589 Use native focus
d71e3a2 Use proper methods for detecting data type in getAnnotationIndexesFromOffset
a930e57 Add optimised method hasAnnotationsInRange
74c729f Use the current document when evaluating activeElement
10aefba Remove is*ArrowKey functions
10465c1 Remove onFocusableHistory listeners
22eb203 Bind/unbind setResizableHandlesSizeAndPosition on focus/blur

Change-Id: I1843ae58fd692c940e4e3d285bfadd3febedca07