Document CoreBundle requirement when DoctrineBundle <1.3

The RoutingBundle Doctrine ORM integration requires CoreBundle to function properly if using DoctrineBundle <1.3.
Add caution directive
Merge pull request #386 from simshaun/1.0

Document potential CoreBundle requirement when DoctrineBundle <1.3
[#386] Minor standard change
documenting sonata admin for menu nodes
Merge pull request #387 from symfony-cmf/menu-sonata-admin-2

documenting sonata admin for menu nodes

Closes #379
fix very old rename
Merge pull request #390 from symfony-cmf/slideshow-block-1

fix very old rename
Added a note for the parent mapping feature
Merge pull request #395 from symfony-cmf/docs-for-57

Docs for 57
[#395] Applied proposed changes
Merge branch '1.0'