Suppress PHP warnings/notices during AtomPub XML parsing to avoid HTTP header problems when given bad input.
Suppress PHP warnings/notices during AtomPub XML parsing to avoid HTTP header problems when given bad input.

If display_errors is on, typical settings would cause PHP error messages to spew to output before the HTTP headers for setting a 400 error go through.
Also switched from deprecated static DOMDocument::loadXML() to non-static call.

sikevux/bsk-social,zh/statusnet,studio666/gnu-social,sikevux/bsk-social,d3vgru/StatusNet,minmb/statusnet,zcopley/StatusNet,foocorp/gnu-social,furtherfield/gnu-social,eXcomm/gnu-social,csarven/statusnet,charlycoste/StatusNet,zh/statusnet,Piratas/tortuga,bankonme/gnu-social,xebia/statusnet-oauth2,zcopley/StatusNet,faulteh/gnu-social,sikevux/bsk-social,chimo/social,furtherfield/gnu-social,charnimda/lgbtpzn-social,furtherfield/gnu-social,minmb/statusnet,faulteh/gnu-social,zh/statusnet,chimo/social,eXcomm/gnu-social,charnimda/lgbtpzn-social,Piratas/tortuga,csarven/statusnet,studio666/gnu-social,eXcomm/gnu-social,faulteh/gnu-social,gnusocial/mainline,bankonme/gnu-social,csarven/statusnet,Piratas/tortuga,charnimda/lgbtpzn-social,UngPirat/freesocial,gnusocial/mainline,eXcomm/gnu-social,charlycoste/StatusNet,sikevux/bsk-social,charlycoste/StatusNet,foocorp/gnu-social,UngPirat/freesocial,gnusocial/mainline,d3vgru/StatusNet,studio666/gnu-social,xebia/statusnet-oauth2,foocorp/gnu-social,bankonme/gnu-social,xebia/statusnet-oauth2,Piratas/tortuga,studio666/gnu-social,bankonme/gnu-social,minmb/statusnet,UngPirat/freesocial,faulteh/gnu-social,gnusocial/mainline,furtherfield/gnu-social,zcopley/StatusNet,d3vgru/StatusNet,csarven/statusnet,chimo/social