Implementing a new $(sys.uptime) variable (Mantis #1134)

The $(sys.uptime) variable contains the number of mintues the system
has been up and running. It uses various techniques depending on the OS
platform to find the system uptime:

* sysinfo() for Linux platforms
* kstat() for Solaris platforms
* pstat_getproc() for HP-UX
* sysctl() for BSD platforms

Any platform which doesn't have one of these methods available will default
to a stat(/proc/1) to get the create time of the init process, which falls
within a few seconds of the boot time of the system. (Even though Linux and
Solaris have /proc, this method is not used on those platforms even as a
fallback.)

If any of these approaches fail, the routine falls back to running the
"/usr/bin/uptime" or "/bin/uptime" command, and its output is parsed into
days, hours, and minutes with a PCRE regexp, and converted to a usable time
for the variable. Thanks to Ted Zlatanov for the suggestion: https://github.com/cfengine/core/pull/46#issuecomment-10066632

This popen() approach is unlikely to be used very frequently - probably only if
the /proc filesystem isn't mounted - but it's a decent backstop to give a
system the best possible chance to set $(sys.uptime) successfully.

Two other closely related variables are introduced: $(sys.systime) and
$(sys.sysday). The former is simply the result of the time() system call,
which is useful in manipulating timestamps in HP-UX TCB password databases,
for example, and the latter is that value divided by 86,400 - the number of
seconds in a day - expressed as an integer. This is, of course, useful in the
/etc/shadow file to indicate the password change date.

Three new documents are added in docs/reference/vars to describe the
$(sys.uptime), $(sys.systime), and $(sys.sysday) variables.
BSD <sys/param.h> include is required for <sys/sysctl.h> header checks

See also jail.h, sys/mount.h checks.
64-bit time_t snprintf; cf_popen needs pipes.h - for sys.uptime var

The cf_popen() and cf_pclose() calls now need to have pipes.h included,
because it was factored out in commit 5be64d09bc4c9c9659d53d2b5bf61286f768acbf.

The time_t type needs the proper printf format to support both 32- and 64-bit
platforms. On older platforms which don't have a C99-compliant snprintf, the
"pub/snprintf.c" replacement is used, so that a "%jd" format can be used even
on such platforms. Normally they would use the PRIdMAX definition from
inttypes.h. See commit f6ba42d5b2988be1f94ee4e55baa174fd7906362.
Added FreeBSD portmaster package_method
Update HACKING
Fix filestat test pass condition.

Pass when all conditions are met, not when any condition is met.
My ChangeLog entries.
fix for redmine #2635
Merge pull request #661 from kacfengine/changelog

My ChangeLog entries.
Merge pull request #652 from sigurdteigen/cleanup/hacking

Update HACKING
s/CfOut/Log to fix compile error
Redmine #2675: /bin/bash is not available on all supported plaforms

The test script test/acceptance/08_commands/01_modules/003.cf.script
uses a /bin/bash shebang, and the Bash shell is not available on
stock HP-UX systems among others, preventing the test from running
properly. This commit changes bash to sh to conform with all the
other test scripts.
Merge pull request #665 from mvpel/redmine_2675

Redmine #2675: /bin/bash is not available on all supported plaforms
Merge pull request #662 from jeffali/fix/2635

fix for redmine #2635
Redmine #2573; correct mistake in placement of pragmas

The #pragma is not allowed inside functions, so move it outside.
Merge pull request #666 from kacfengine/hpuxFix

Redmine #2573; correct mistake in placement of pragmas
Take alternative workdir into account in test.
Merge pull request #667 from kacfengine/testFix

Take alternative workdir into account in test.
Wrong signature for mocked function

In logging_test.c we mock "sendto" to avoid sending data. In HPUX the compiler
is a little bit more strict than anticipated so it was complaining about the
type of the signature. It is interesting that this worked all over the place
and no other compiler complained even though it is evidently a failure.
Merge pull request #669 from cduclos/master

Fixing an evident compilation failure