Remove unused dconf profile; rename site snippets

- Remove the dconf user profile, another package will
  provide it.  (Due to 4ca10f2d being added after the changelog
  for 1.40 was finalized, 1.40 did not actually install these,
  so we do not need to rm_conffile them.)
- Rename the site db snippets to the package name, and
  change the prefix from 00 to 10, in case we ship a base config
  later
- After installation, we must call "dconf update" to rebuild
  the binary databases.  We need to depend on dconf-cli for this
  (which is still called dconf-tools in Precise)