minor update
Replaced generics in K,V,R (parsers) in generics on the processor.
This has the unfortunate side effect of requiring Singleton.
Now trying to move the conversion methods inside UserCtx.

This is not a final version.
last commit uncomplete
Moved userCtx into Binder.
in progress
improving Tutorial to solve all problems
Tutorial mostly OK.
Checking now derivation between parsers/processors
Tutorial done.
Updating code.
Works!
Most drawbacks are removed, in particular the too strong parser <->
processor dependencies we had before.
Cleanup required (read bottom of CtxTest)
Continuing cleanup.
Framework likely stable now (?)
Check bottom of CtxTest for current immediate tasks (include mostly.)
include in progress
Include in progress (unsafe.)
How do one make safe includes ???
uncomplete commit
"Final" version for the core.
It should now see little changes.
Merged to master.