Copy paste tables from MS Word to IE does not create several tables.

When copying and pasting tables from Word to IE several tables were created, one table for each row instead of one unique table. This was due to 2 problems: the generic content handler was not set and a bug in the pasting code. Generic content handler sanitizes the copied content. The second problem is that an element is unwrapped if this is the only element in the paragraph. With this fix if the element is unwrappable (table, tbody, ..) the unwrap is not done. For Firefox or Chrome this not happens because the paragraph has always more than one element because it contains empty elements.
Merge pull request #1121 from najor/hotfix-rt57667-copy-paste-tabelle-ie

Copy paste tables from MS Word to IE does not create several tables.