DraCor API 1.3.0 and other updates

In the wake of the latest release of DraCor Schema release we also updated several other components of the DraCor ecosystem:

• the DraCor API 1.3.0 supports the new markup introduced with DraCor Schema 1.4.0 while remaining compatible with previous schema versions.
• the DraCor Validate Action 2.4.0 has been updated to the latest DraCor Schema and TEI versions.
• the first official release of the DraCor Oxygen Framework makes it easier to validate DraCor documents in the Oxygen XML Editor and to stay up to date with DraCor Schema releases.