bug fix: URLs must be URLencoded when editing

editResource failed to URLencode resources in one case,
which caused URLs to be decoded in XSLT without first
being encoded.
Remove unnecessary internal URL encoding/decoding
move createParametersMap() method to Form2SparqlService,
removing 5 copies from other classes.
Use JNDI instead of hard coded database parameters
move duplicate code from Login.java and LoginController.java to new class LoginService.java
Also, show an error message if the user database is unavailable.