Changeset 2463 for trunk/tools

feature 839, first step : early proof of concept, no error handling. A
remote client can add a photo in a category thanks to the web API. A new
"upload" directory is created (write access required on the base
directory). Uploaded photo have path such as
upload/<year>/<month>/<day>/<datetime>-random.jpg. The thumbnail must come
with the "web sized" photo. The photo has no storage_category_id.

Bugs still need to be fixed and a discussion must occur before next steps.