Try to be explicit at redirection doc.

In addition to the string "@I" as identifier to replace by the name of instance service,
the following identifier are now recognize :
@I, @U, @u, @G, @g, @H, @S, @R. see doc/66-identifier.md for furthers information.

clean of string from frontend key for module.
fix value of intree key.
allow sufficient space for rename of interdependences.
fix use of parse_list functions even in case of multiple line.

This reverts commit 87bd69c6.

Reduce use of HEAP memory with
the stack_xxx functions familly.
Switch to the new lexer algorithm.
Fix the parse of the @runas key.

simplify interface of service_is_g and its functionality, provide service_get_treename as replacement