Fix timestamps in fallback content for EventPlugin
Fix timestamps in fallback content for EventPlugin

A bunch of the common_* functions for date formatting expect an interpretable string, rather than a Unix timestamp, as input. Switched to using the DB-formatted timestamps as we put them into the object rather than the unix timestamp intermediate value when formatting the plaintext and HTML fallback content.

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