If you make any changes to the HTML, Javascript, css (anything apart from the Java files) Jetty will automatically pick up the changes so a browser refresh should get the new content. There is no need to restart jetty. If you change any Java files running mvn compile while also running mvn jetty:run jetty will ensure jetty picks up any changes
Mirador is included in the SimpleAnnotationServer to aid quick deployment. If you would like to update Mirador follow the instructions on the Mirador Site and copy everything from mirador/build/mirador/* to src/main/webapp/mirador.
It is possible to overload any of the configuration specified in src/main/webapp/WEB-INF/sas.properties by prepending SAS. to any of the properties in sas.properties e.g:
export SAS.store="solr"