EPIC - Allow the exploitation of data schemas

[benoitdm-oslandia]

"Feature" defines additional features on GET: [schema for update/replace](http://docs.ogc.org /DRAFTS/20-002.html#feature-representations)

• pbm of container modification by other applications ==> pbm of cache

• [x] #5

• [ ] #6

[benoitdm-oslandia]

marked this issue as related to #7

[benoitdm-oslandia]

marked this issue as related to #8