#136 Added environment variable APP_ROOT_PATH to expose the webapp behind a reverse proxy using subfolder. Minor changes to html pages to remove absolute path for some resources

src/main/resources/application.properties

@@ -17,8 +17,9 @@ server.error.include-exception=true
 server.error.include-message=always
 
 server.servlet.session.tracking-modes=cookie
+server.servlet.context-path=${APP_ROOT_PATH:/}
 
 spring.devtools.restart.enabled=true
 spring.devtools.livereload.enabled=true
 
-spring.thymeleaf.encoding=UTF-8
+spring.thymeleaf.encoding=UTF-8