Two new routes:
* `GET /{_locale}/person/api/1.0/accompanying-course/{parcours_id}/show.json`: get a json representation for a course
* `POST /{_locale}/person/api/1.0/accompanying-course/{parcours_id}/participation.json`:
add a particitipation to course. Usage:
`curl -v --cookie "PHPSESSID=fed98aa23e40cb36e630f84155aea3bb;" -X
POST --data '{ "id": 481 }'
http://localhost:8001/fr/person/api/1.0/accompanying-course/270/participation.json`
Will add the person with id "481" to the course.
fixes : A new entity was found through the relationship 'Chill\PersonBundle\Entity\AccompanyingPeriodParticipation#accompanyingPeriod'
that was not configured t o cascade persist operations for entity: Chill\PersonBundle\Entity\AccompanyingPeriod@0000000002b1d44a000000002510e4e2.
To solve this issue: Either explici tly call EntityManager#persist() on this unknown entity or configure
cascade persist this association in the mapping for example @ManyToOne(..,cascade={"persist"}). If you cannot find out which entity causes the problem
implement 'Chill\PersonBundle\Entity\AccompanyingPeriod#__toString()' to get a clue.
