* doc/sources.list.5.xml:

* doc/sources.list.5.xml:
  - Mentioned allowed characters in file names in /etc/apt/sources.list.d.
    Thanks to Matthias Urlichs. (Closes: #426913)
* doc/apt-get.8.xml:
  - Included '-v'/'--version' as a command to synopsis.
* cmdline/apt-cache.cc:
  - Advanced built-in help. Patch by Andre Felipe Machado. (Closes: #286061)
  - Fixed typo 'GraphVis' -> 'GraphViz'. (Closes: #349038)
  - Removed asking to file a release-critical bug against a package if there
    is a request to install only one package and it is not installable.
    (Closes: #419521)