Fix compilation error on FreeBSD

timezone is defined differently in FreeBSD compared to other
(more or less) POSIX-compliant Unices.

Task-number: QTBUG-36080
Change-Id: I4ad1a5ccd0b9ddbadb9fdd90edc26cf0c7252dfb
Reviewed-by: Thiago Macieira <thiago.macieira@intel.com>
Support logging direct to journald, if enabled.

Instead of merely intercepting logging output from stdout/stderr from the
journal side of started processes, this has the advantage of meaning that the
origin process name will be correct.

fprintf won't work, because if a process starts children (like e.g. a
homescreen does), then their stdout/stderr are merged into their parent, and
journal has no way of differentiating the origin.

We are also able to store information about the context of logging, which might
be useful in post-mortem cases.

[ChangeLog][Platform Specific Changes][Linux] Systems with systemd may now pass
-journald to configure to send logging output to journald. Logging will still be
sent to stderr for interactive applications (run from a tty) or with
QT_NO_JOURNALD_LOG set to a non-empty value.

Change-Id: Ib260cec1ea87390bf44f267d217d795583407d00
Reviewed-by: Thiago Macieira <thiago.macieira@intel.com>