Add optional title attribute to the code examples

Add optional title attribute to the code examples, let the show_in_doc and title keys survive example regeneration (with added config flag)

The problems I had with the previous pull request where resulting from the usage of `spring`. When using `spring testunit` with the APIPIE_RECORD env variable it will mess up the version detection. The examples will be written with -versions: []. I have not figured out why this happens, however it is unrelated to my changes.

Let me know if there are any changes you need before you can merge this.