pfPorts/php52: Sync against FreeBSD Ports r317389

Only things related to the port itself but not much the port, minor stuff only.
(now with correct references)

From r312481
Author: miwi <miwi@FreeBSD.org>
Date:   Mon Feb 18 06:00:58 2013 +0000

    - Extend support for 6 months.

    PR:		176149
    Submitted by:	Alex Keda <admin@lissyara.su>

From r312482
Author: miwi <miwi@FreeBSD.org>
Date:   Mon Feb 18 06:01:51 2013 +0000

    - Trim header

r317158
Author: bapt <bapt@FreeBSD.org>
Date:   Sat Apr 27 22:09:15 2013 +0000

    Convert the last USE_ICONV to USES=iconv

From r317158
Author: jgh <jgh@FreeBSD.org>
Date:   Thu May 2 21:53:51 2013 +0000

    - conversion to USES=gettext

    Approved by:	portmgr (bapt@)

From r317389
Author: flo <flo@FreeBSD.org>
Date:   Sat May 4 22:48:03 2013 +0000

    Fix installation of ports that rely on cp -n for installing files. r245960
    changed cp to exit with a non-zero exit code if the file exists and is not
    overwritten thus causing ports to fail installing when e.g. trying to cp
    .default -> .conf files that already exist.

    We just ignore the error and continue, as we used to.

    Reported by:	jaset
    Approved by:	portmgr (bapt)