Do not replace stdout in child worker process.

Unidentified spurious problems on Solaris 9, with file descriptor 0
*not* corresponding to stdin, triggered me to change the worker child to
not close its stdout and replace it with the dup()ed pipe
descriptor. Instead, it now fprintf()s directly to that pipe.

Didn't fix the problem on Solaris (still investigating) but still its a
good change.
pthread_cond_timedwait() takes absolute time

Also fix threads actually delivering the signal when they should.
This fixes test failure on Solaris.
Using high precision clock should avoid corner case...

where time(NULL) returns e.g. 5, but time is 5.99.
Thanks to @kacfengine for spotting this.
Merge pull request #1778 from jimis/lastseen_threaded_load_fix-redmine6103

Lastseen threaded load fix redmine6103
Redmine#5209: string_downcase the eval result for AIX and Solaris
Redmine#6220: on Solaris 10 acceptance tests, use a Perl sort to enable 10_files/02_maintain/changes_depth_search.cf
A bit doc.
Rename process_finish() to process_replace().
cf-upgrade shouldn't include from lmdb, postgres etc.
Preserve environment through exec.

For example dpkg requires PATH environment variable.
Silence a number of compiler warnings.
Merge pull request #1783 from vohi/compiler_warnings

Silence a number of compiler warnings.
Merge pull request #1774 from jimis/cfupgrade

Simple doc, Makefile, and cherry-pick error fixes.
Windows version needs to be renamed as well.
Merge pull request #1784 from jimis/cfupgrade

Windows version needs to be renamed as well.