* doc/examples/configure-index:

* doc/examples/configure-index:
  - Removed obsoleted header line. (Closes: #417638)
  - Changed 'linux-kernel' to 'linux-image'.
* doc/sources.list.5.xml:
  - Fixed typo and grammar in 'sources.list.d' section. Thanks to
    Timothy G Abbott <tabbott@MIT.EDU>. (Closes: #478098)
* doc/apt-get.8.xml:
  - Advanced descriptions for 'remove' and 'purge' options.
    (Closes: #274283)
* debian/rules:
  - Target 'apt' need to depend on 'build-doc'. Thanks for Peter Green.
    Fixes FTBFS. (Closes: #504181)