Split functional test runs in tiers

We want the most important tests to go through first, then the other tests.

Most important on nuxeo/nuxeo are:

• nuxeo-server-tests
• nuxeo-server-hotreload-tests
• nuxeo-server-cmis-tests
• nuxeo-server-gatling-tests

Most important on nuxeo/nuxeo-jsf-ui are:

• nuxeo-jsf-ui-webdriver-tests
• nuxeo-platform-error-web-tests
• nuxeo-platform-forms-layout-demo-tests
• nuxeo-jsf-ui-hotreload-tests

Introduce new Maven profiles in the ftests/pom.xml to split the functional tests in 2 tiers:

• tier 5: the most importants ones
• tier 6: other tests
  Tiers 1-4 are kept for the unit tests.

The profiles are disabled by default and can be activated using a maven property such as nuxeo.ftests.tier5.

<profile>
  <id>ftestsTier5</id>
  <activation>
    <property>
      <name>nuxeo.ftests.tier5</name>
    </property>
  </activation>
</profile>