Table refresh method for 1.3.x. Fixes #5841 and fixes #5842.

Branch table-refresh-1.3 has been created out of 1.3-stable.

@frequent's commits from PR #5845 (except the "merge branch master" commit) have been cherry-picked into this branch. After that another two PR's (each containing one commit) have been merged into this branch.

Branch table-refresh-1.3 will be merged into branch 1.3-stable so none of these commits will land in branch master. Those refresh methods for the table widget are only meant for 1.3.1 and following 1.3.x maintenance releases.