responsive menu fix - data-target attribute added

responsive menu fix - data-target attribute added

- petclinic.css is now auto generated, therefore it is put in the
ignore list
- vendor folder is removed in favour of webjars
- remove several maven dependencies which are already managed by spring
boot
- unfortunately, lesscss maven plugin does NOT support importing from
classpath, as a result, bootstrap is unpacked during process-resources
phase, we need need to find a better resolution
- remove bower integration

abstract the page layout into “layout.tag”

abstract the page layout into “layout.tag”

CallMonitoringAspect is not invoked when spring-data-jpa is used.  Spent
4 hours trying to understand why jmx bean wasn't showing message counts.
Use JPA or JDBC if you want call counts exposed via JMX / AOP

RSS is becoming outdated, JSon is a better example

We were planning to create a ‘help’ but it never happened

Took that opportunity to use custom tag (14 lines versus 2 lines)

 * The old datatables-servlet2 dependency has been removed from the pom.xml
 * Some attributes have been renamed (e.g. paginate => pageable)
 * Starting from the v0.10.0, all web components (servlet, filter) must be explicitely declared in the web.xml file. That's why I added the following declaration: DandelionFilter, DandelionServlet and DatatablesFilter
 * Added a new datatables.properties file in order to disable the asset management brought by Dandelion-Core. This is equivalent to the old cdn=true table attribute

adding explicit reference to default profile because it doesn't seem to work on on some environments