Key name now begin with a capital letters instead of using the '@' character.
Also, '-' character are removed from  a composite name.
This is introduce the very first change of the key field.
Some simplications and changes to the key name will be made.
Add the  get_enum_list() function.

This program is executed via the run script in the service's live directory. It sits between s6-supervise and the user's executable script, allowing for the preparation of the user's script execution. This introduces a dual capability:

    Define certain preparations through frontend keys, such as setting ownership, moving to a working directory, limiting resources used by the service, etc.
    Since 66-execute runs on each signal received and transmitted by s6-supervise, it is now possible to send messages to an event management daemon.

By default, this program performs previously defined actions such as logging redirections and managing environment variables (previously handled by excel-envfile), creation of the log destination directory, and so on.So, the user's file now contains only the exact copy of the @execute field.
Also, the name of the script for an start or
stop process are the same. This was a old behabvior
coming from s6-rc  manager.

Permit to set uid and gid for a run script.
Unknown key may occur at end of the file.
Avoid to changed pointer.
Typo fix.

Splitting through a wrapper the main parse_section
allow to be flexible in case of specific needs for a section.
It also easier to add another section.

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.