OpenXML: strip <w:noProof> during filtering

[Chase Tingley]

This is another spelling/grammar check-related run property, which breaks up segmentation. Runs that differ only in terms of this value should be merged.

[Chase Tingley]

I have a fix for this on the tag-rework branch.

[Chase Tingley]

Fix Issue #506 - strip <w:noProof> element to improve segmentation

→ <<cset d5b034debcfa>>

[Chase Tingley]

Reopening this because it's only fixed on a branch (tag-rework); the commit comment auto-closed it.

[Chase Tingley]

Fix Issue #506 - strip <w:noProof> element to improve segmentation

→ <<cset 78f07f222302>>