Updated XSLT

Hi,

I’m using the XSLT openEHR_RMtoHTML.xsl (found here https://openehr.atlassian.net/wiki/display/dev/openEHR+Composition+XML+to+HTML?focusedCommentId=32014341#comment-32014341) to format XML compositions into HTML in the EHRServer (https://github.com/ppazos/cabolabs-ehrserver).

Recently I added support to DV_IDENTIFIER and DV_DATE to the EHRServer and noticed those DVs weren’t supported by the XSLT, so I added them: https://github.com/ppazos/cabolabs-ehrserver/commit/a97047aee7f418fe38b9c58d228742c992aca405

Feel free to grab it from my repo. If there is any official openEHR project that uses that XSLT, I can send a pull request. Just let me know.