'scope' attribute set to 'column'

The 'scope' attribute of 'th' tag element not accept 'column' value.
The values accepted for this attribute are 'col' or 'row'.
Merge branch 'hotfix-table-th-scope-column-rt56088' of github.com:najor/Aloha-Editor into najor-hotfix-table-th-scope-column-rt56088

Conflicts:
	build/hotfix-changelog.md