Add Turtle support for ktbs, and optionalize handshake call
Modify prototype declaration style

It is useless to add another variable there.
Use <model#> relative URI for trace model in turtle serialization
Use post= parameter for GET requests

in order to be compatible with the ktbs API
Factorize the get_stats() method
Use get_stats() method for generating index
Implement /stat/user/ and /stat/user/<foo> paths

They return JSON data containing stat info
Update init_trace API
The url parameter is now the trace URL, not the baseuri
Add a trailing / to avoid a redirect
Add missing ;
Add parameters to test method