[2.3.x] Fix for https://java.net/jira/browse/GRIZZLY-1555 (WebappContext needs to convert "." to a real path in order for getResourcePaths() to function properly.)
[2.3.x] Fix for https://java.net/jira/browse/GRIZZLY-1126 (Response.sendError(...) should return html error page).
[2.3.x] Fix copyright.