Fine to let GetObjectItemPool return just SfxItemPool*

Change-Id: Id461dea979c394add57cbc4b1a50bc1a4c183d1b
writerfilter: bin OOXML_something duplication of oox::XML_something constants

workdir/CustomTarget/writerfilter/source/ooxml/OOXMLFastTokens.hxx was a
duplication of workdir/CustomTarget/oox/generated/oox/token/tokens.hxx,
except when the oox generator changed, the writerfilter copy was not
adjusted and Bad Things happened. We don't need this.

Change-Id: Id92481f110b04ec24cb424421aa0ec029b7896f3