simplify cmf documentation like core documentation

[dbu]

symfony documentation got cleaned up. one major part was the integration of the cookbook articles into the general documentation. for background, see http://symfony.com/blog/introducing-the-new-symfony-documentation

i think we should do a similar thing with the cmf documentation.

[wouterj]

See also #523 (comment)

[dbu]

looking at the symfony doc, we should get rid of the section "cookbook" but its ok to keep "stuff" that does not fit into a specific bundle. i guess thats mainly the distribution installation instructions - though those might also better be moved back to the readme of the respective repository. or the guides to choose storage system and jackalope version.

[dbu]

@wouterj would you agree that we close this issue and do one to get rid of most cookbook things except those that don't fit into a specific bundle? or is there anything else we should still do? (the book is gone, and there is a task to get rid of the tutorial)