updated cda samples

Samples updated to remove validation errors found using the Lantana CCDA
validation tool at
https://www.lantanagroup.com/validator/connectathon.jsp
Update README.md

Additional information about validation errors, and updated xml sample.
updated to fix c-cda scorecard warnings
generating correct time value within serviceEvent
moved xsl
Update breast surgery.xml
Update breast surgery.xml
Revert "moved xsl"

This reverts commit aab98ae2e4e081c3b39e73f9da0dedc78e584a1f.
Revert "Revert "moved xsl""

This reverts commit 4e3cbdd4e68e1d9d237169c3e0059acbab2f4b40.
changed xsl path
changing style sheet path to get github raw view to load xsl
Revert "changing style sheet path to get github raw view to load xsl"

This reverts commit d7e3460ecbea33dd47724c1c643b46beb05ff709.
Update README.md

added a link to ccda scorecard
Merge pull request #6 from peteot/master

OpNote CCDA samples updated