Have a t-call having a t-raw="0"
that call is made to a template of the same form
i.e. itself as a t-call t-raw="0" structure
Before this commit, there was recursion crash
This was because the caller to which a t-raw="0" referred to
was incorrect. The caller here is the node which makes the t-call.
In particular, the caller was always set to last caller of the context
After this commit, there is no crash and this imbrication
of t-call and t-raw="0" is well rendered.
To sum up, we count the recursive calls to t-raw="0" and fetch
the caller in the context accordingly
closes#510
Géry Debongnie