ADDED: library(sandbox): writeln/1 as safe.
Updated jpl
FIXED: qsave_program/2 failed with autoload(false)

The cleanup in commit 8f6a3ee28795c0bed893974ad07d0122be67b81c caused
qsave_program/2 to fail anytime the autoload option was set to false.
This restores the intended behavior of skipping autoload/0 in that case.
Merge branch 'master' of github.com:SWI-Prolog/swipl-devel
ENHANCED: Try to avoid messages about the thread pool manager not existing while terminating the process
BUILD: Added missing dependency to support parallel build.  Roberto Bagnara.
Updated http
Updated pengines
Updated pengines
FIXED: Avoid type error on arg(_, atom, _).  Samer Abdallah.
Added predicate options declaration.
MODIFIED: meta_predicate/1 declarations associate the declared predicate
with the source file being loaded.   Reloading a file _clears_ meta
predicate declarations.
ADDED: list_void_declarations/0 to list predicates that have declarations
such as meta_predicate/1 but no clauses.
ADDED: make/0 calls list_void_declarations/0
Updated pengines
Small update
Updated http
ADDED: timeout and deadline options to thread_send_message
Updated syspred_options.pl to reflect new thread_send_message/3.
FIXED: Wrong declaration (new warning).  Jacco van Ossenbruggen.