* doc/files.sgml:

  - sync documentation with status quo, regarding files/directories in
    use, extended_states and uri schemes.
* doc/cache.sgml:
  - drop the file in favor of inplace documentation with doxygen
* apt-pkg/pkgcache.h:
  - enhance the Groups ABI by providing a ID as the other structs does
  - check also the size of the Group struct then checking for the others

diff --cc apt-pkg/depcache.cc
Simple merge

diff --cc apt-pkg/pkgcache.cc
Simple merge

diff --cc debian/changelog
Simple merge