FIXED: variant_sha1/2 gave same hash for all _indirect types_ (big integers,
floats and strings).  Jacco van Ossenbruggen.
Added vm_list() proptotype.
FIXED: link local variable if it appears as Var:G or G@Var.  Without,
uninitialised memory may be used for Var, causing a crash.  Guenter Kniesel.
ENHANCED: Base stack traces in Linux on backtrace(), dladdr() and
addr2line(1).  This produces stack traces at the line level and removes
the need for libunwind on Linux.
DOC: Updated open/4 (Wouter Beek).
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.
BUILD: Added missing dependency to support parallel build.  Roberto Bagnara.
FIXED: Avoid type error on arg(_, atom, _).  Samer Abdallah.
FIXED: Wrong declaration (new warning).  Jacco van Ossenbruggen.
FIXED: Location in error message when reading from a stream swapped
line and line position.
FIXED: JIT clause indexing could mis the right argument in the following
scenario:

  - There is a best index Ib, which is poor.
  - There is a normally better index I2, but the corresponding
    argument is not indexable.

Although the scenario is not that common, it can lead to a huge
slowdown.  Found by Jos de Roo.
ADDED: library(prolog_colour): meta_declarations(Extra) to support variations
on meta-predicate declarations.
FIXED: format_time/3: %f rounding.  Igor Wojnicki.
FIXED: Allow colouring options for predicates that have otherwise specified
colour instructions.  E.g., the 2nd argument of load_files/2.
Fixed warning that -Asize and -Hsize no longer exist
DOC: Path for MacOS app commandline version.  Ognjen Savkovic.
FIXED: '$qlf_include'/5: inconsistent representation of files.  Causes
problems if :- include/1 is the first term of a file.  Douglas Miles.
FIXED: Do not save anything from volatile predicates that are
not dynamic or multifile.
FIXED: Prepare for errors while reading the history.  Philippe Chatalic.
FIXED: Possible crash reloading a file.  Jacco van Ossenbruggen

(hand-copied from 47100fd1c436d58e9ff767db5fc7592e926077bd)