Commit original strndup.m4 from gnulib, modifications in next commit.
fix failing acceptance test by fixing ps opts
Redmine #5211: Detect broken strndup on AIX and provide workaround.

This fixes some *very* elusive crashes, that happen pretty much
anywhere in CFEngine, the reason is that strndup(src, n) on AIX has a
bug which allocates memory for strlen(src), but it will *write* n
bytes, so whenever n > strlen(src) you get memory corruption.
Merge pull request #1829 from kacfengine/aix_broken_strndup

Redmine #5211: Detect broken strndup on AIX and provide workaround.
Fix cf-upgrade's self-copy in windows.
Suppress some more test failures on AIX.
Merge pull request #1830 from MatthewCattell/modify-solaris-ps-opts

fix failing acceptance test by fixing ps opts
Work around AIX forcing the primary group to be part of secondaries.

Fixes test case 17_users/unsafe/promise_outcomes.cf.
re enable mon_processes_test for solaris
Merge pull request #1834 from kacfengine/aix_forced_secondary_group

Work around AIX forcing the primary group to be part of secondaries.
disable acceptance tests failing on solaris
Merge pull request #1838 from MatthewCattell/solaris-disable-failing-acceptance

disable acceptance tests failing on solaris
Merge pull request #1835 from MatthewCattell/solaris-unit-test-re-enable

re enable mon_processes_test for solaris