fetch keywords which support arguments do not support being called
without parenthesis even if all arguments are optional. Let's fix
this to allow fetch keywords without parenthesis as is already done
in ACLs.
It appears that fd.h includes a number of unneeded files and was
included from standard.h, and as such served as an intermediary
to provide almost everything to everyone.
By removing its useless includes, a long dependency chain broke
but could easily be fixed.
