[#20] Integrate latest version of apt, apache2 and php cookbooks

[gildegoma]

• PR related to #20 proposal
• 3 commits voluntarily not rebased, to allow discussion/cherry-pick, since guide lines of #20 are not frozen.
• As Learning-by-doing example, I voluntarily opened the PR with branch 'pr3' as target. The merge process I have in mind is following:
  1. branch pr3: #20 issue is identified and proposed during implementation/review of #3 (for PHP and Apache). Even if #20's scope is larger than #3, we don't want too much git-administration and keep the focus on the hot topic (#3). Known Problem: This pull request cannot be automatically merged. (maybe because origin of pr20 is master, not pr3)
  2. master: Once #3 is accepted, #20 will also be merged

With my little git experience, I preferred this approach compared to:

• update pr3 branch with out-of-subject changes
• PR pr20->master may lead to more extra work to manage merge/changes between branches

[gildegoma]

As expected for my learning by doing exercise, pr3 and pr20 conflict. Hot Point: how to handle submodule reference conflicts... ;-)

Boskop private-server (pr3)$ git merge pr20
Auto-merging cookbooks/php
CONFLICT (submodule): Merge conflict in cookbooks/php
Auto-merging cookbooks/apache2
CONFLICT (submodule): Merge conflict in cookbooks/apache2
Auto-merging .gitmodules
CONFLICT (content): Merge conflict in .gitmodules
Automatic merge failed; fix conflicts and then commit the result.

[gildegoma]

I keep discussion #20 about external cookbook management open, but for now I won't block/disturb branch pr3 (#3 and #16) with this point. new PR from pr20 to master will come when guidelines are adopted