This prevents overwriting executable binaries, something which
confuses the code signing logic on macOS.

This was broken in multiple ways:

* Did not consider timestamp on aclocal.m4
* Did not consider post_modules
* Did not check configure scripts directly under modules or post_modules
* When fixing modules, it looked for the configure scripts in the build
  directory rather than the source directory
* Did not use the run_autoconfig wrapper

This has caused xenofarm to export snapshots with out of date
configure scripts.

Reorder the assignments of EXIT and EXITCODE, so that the
assignment of EXIT doesn't clear $? before it is used for
the assignment of EXITCODE.

Fixes [PIKE-40].

this should prevent "compiled against version x but linking against version y" warnings.

Gnu-tar doesn't like being asked to extract the same file multiple
times from the same tar-file. It claims that the second file doesn't
exist in the archive.

This can happen when a sub-package has been replaced with a fixed version.

build: smartlink chooses better deployment options on new releases OSX, should help with C++ library compatibility

Make sure that the first string in the mkdirhier loop has the
correct character range by preloading the initial non-empty string.

Needed by the Roxen build system.

Make sure that the $EXTRA_PLATFORM_TEST file (if any) comes after
the install script in the generated tar file, so that it becomes
part of $CONTENTS when the installer is executed.

Fixes issue where the $EXTRA_PLATFORM_TEST file wasn't extracted.

Fixes [bug 7740] some more.

This is intended to be a script to test that the destination platform
has sufficient prerequisites installed.

Also makes the install script return the exit code from the installer.

Preparation for fixing [bug 7740].

This can cause the export to hang and/or fail.

A short-hand notation may now be used to match operator calls.
Eg the following fragment:

  F_APPLY(F_CONSTANT[TYPEOF($$->u.sval) == T_FUNCTION]
		    [SUBTYPEOF($$->u.sval) == FUNCTION_BUILTIN]
		    [$$->u.sval.u.efun->function == f_ge],
	  F_ARG_LIST(X, Y))

can now be written as:

  F_GE(X, Y)

Converted from using static to using protected.

Fixes the support for LONGUPPERDELTA (which caused the broken
lower_case tests).

Cleans up the code somewhat.

The reference count for reused nodes needs to be bumped once
for every occurence...

This bug was triggered at least by the empty loop ==> assignment rules,
with the effect that the free list in block alloc got corrupted.

Example code that triggered the bug:

  int i;
  array a;
  for(; i < sizeof(a); i++)
    ;

printf is not available on many unix like system (e.g. embedded ARM fan
controllers). cat with here-document should be even more widely
available. Thanks to Chris Angelico for proposing this solution.

backslashes in arguments to echo are undefined. more specifically, in
some implementations backslash escapes will be interpreted, in some they
won't. printf should be fine.

Revert "whitespace: removed extra escape"

This reverts commit a2ecb8f8.