Update VE core submodule to master (1fa7b5f)

New changes:
c79a46e Updating scalable default in MediaSizeWidget
7bf9c7e Cache references in handleDelete
e5f74b7 unicodejs: Update moveBreakOffset to include 'HebrewLetter' category
a5b21b6 Fix watch list
6508e88 Directionality fixes in SA demo
dd71c16 Localisation updates from https://translatewiki.net.
4ed85b9 Localisation updates from https://translatewiki.net.
b6fc28a Special case for deleting the entire document
ddd6372 DebugBar tidy up
6160868 unicodejs: Add tests for hebrew letters in moveBreakOffset
1fa7b5f Update OOjs UI to v0.1.0-pre (7b3672591f)

Change-Id: I2dbcf1d7a9829e165bbd0b14da526638d9a7efd5
Merge "Update VE core submodule to master (1fa7b5f)"