EZP-21319: allow mulitple titles on the same level
EZP-21319: add level attribute on title element
EZP-21319: transformations for heading levels
EZP-21319: updated tests for titles with explicit level
EZP-21319: added additional tests for lossy conversion
EZP-21319: updated docs on ezxml lossy conversion fixtures
EZP-21319: tests: add seventh level heading
Merge pull request #740 from ezsystems/fix-EZP-21319-RichText-haedings

Fix EZP-21319: explicit heading levels