Correct spelling ('overridden')
Merge pull request #410 from sbesson/theme_cleanup

Remove plonematch theme from OME documentation
merge dev_4_4 -D org -I include -E exclude: PR 368 (Cpp: Correct content and markup)
merge dev_4_4 -D org -I include -E exclude: PR 409 (Doc patch dropbox dev 4 4)
merge dev_4_4 -D org -I include -E exclude: PR 411 (Doc patch importer cli dev 4 4)