node management page: Improves the default theme of the "There is no @type" to be shown in a fieldset

correctly obey page access when determining the redirect target and when display submit like redirect buttons,
added the page type to the route's page index

node management page: changed fieldgroup titles on the overview page, to show only the number, if there are more than 1 node of this type allowed

allow page types to work with multiple content types

readded the old 4.7 feature for node management pages: optionally display a node add form instead of an empty overview,
made it possible to label the add button of node management pages' empty overview different than the add button for a non empty overview

added the possibility to make a page that doesn't appear as tab if tab like submit buttons are enabled,
fixed a possible wrong handling of the destination paramter with the PAGEROUTE_NONE redirect target

pageroute nodefamily: fixed automatic loading of pageroute arguments for lonely node types with no given user id

* added a new pagerouteapi hook operation 'boot' which allows customizing page access, have a look at the API documentation for more on this
* changed pageroute_page_arg() to work on $route, instead on  $page.
feature changes:
* overhauled states module integration: used it to optionally verify that a user can only reach the next step, which is ensured through altering page_access. pageroute_nodefamily does now also obey this setting.

new features: now a customized redirect path may be specified, to which users will be redirected after completing the route,
restructured drupal message deletion: page types can now prevent the deletion of the drupal messages and they will be only deleted on form submit!

added states module integration for pageroute nodefamilies, this is working similar as the experimental pageroute workflow integration and will be its superior

fixes destination paramter handling: now pageroute redirects correctly from the last page to the destination paramter