HTTP: Fix Content-Length array index

This patch fix a static workaround implemented to by pass a double
definitions of headers strings, it basically did two things:

 1. Use the MK_HEADER_CONTENT_LENGTH macro
 2. On header.h move some definitions to the .c file

Signed-off-by: Eduardo Silva <eduardo@monkey.io>
Auth: use new HTTP Parser API to manage Authorization header

Signed-off-by: Eduardo Silva <eduardo@monkey.io>
CGI: use new Monkey structures to handle sessions and requests

Signed-off-by: Eduardo Silva <eduardo@monkey.io>
Dirlisting: use new Monkey structures to handle sessions and requests

Signed-off-by: Eduardo Silva <eduardo@monkey.io>
FastCGI: use new Monkey structures to handle sessions and requests

Signed-off-by: Eduardo Silva <eduardo@monkey.io>
HTTP: Parser: register headers in a parser linked list

This patch implements a linked list in the parser so when a known header
or extra headers are found, they are linked to the list so any plugin
can iterate them without problems.

Signed-off-by: Eduardo Silva <eduardo@monkey.io>
Merge branch 'fastcgi_upgrade'
FastCGI: iterate headers using new Parser Headers list

Signed-off-by: Eduardo Silva <eduardo@monkey.io>
Logger: use new Monkey structures to handle sessions and requests

Signed-off-by: Eduardo Silva <eduardo@monkey.io>