oox export: associate editeng CharInteropGrabBag with sw via SID

Change-Id: If25356aa88f435e53b6014773e23d18723507053
oox: change w14 CharGrabBag so it is recognised by export

Change-Id: I7b6f4e5ff9d6e1161b3d05c594498d7f0cb7d8a3
oox: roundtrip-test for w14 elements in groupshapes

Change-Id: I51152c016d6a9e9604fd93c115577020373d964c
oox: add missing break statements

Change-Id: I032442e0e1c583228d6837dbf290f31d01a91b45
ooxml round-trip tests: Move w14 tests to its own test suite.

Change-Id: I42c7cd0aef3f9811440e70d8ea2c31432e1d32ff