navbar, reorganized JSP folders

.../springframework/samples/petclinic/web/VetController.java

src/main/webapp/WEB-INF/jsp/exception.jsp

src/main/webapp/WEB-INF/jsp/fragments/bodyHeader.jsp

src/main/webapp/WEB-INF/jsp/fragments/footer.jsp

src/main/webapp/WEB-INF/jsp/fragments/headTag.jsp

...ain/webapp/WEB-INF/jsp/owners/createOrUpdateOwnerForm.jsp

src/main/webapp/WEB-INF/jsp/owners/findOwners.jsp

src/main/webapp/WEB-INF/jsp/owners/ownerDetails.jsp

src/main/webapp/WEB-INF/jsp/owners/ownersList.jsp

src/main/webapp/WEB-INF/jsp/pets/createOrUpdatePetForm.jsp

src/main/webapp/WEB-INF/jsp/pets/createOrUpdateVisitForm.jsp

src/main/webapp/WEB-INF/jsp/vets/vetsList.jsp

src/main/webapp/WEB-INF/jsp/welcome.jsp

src/main/webapp/WEB-INF/petclinic-servlet.xml

src/main/webapp/resources/css/petclinic.css