Remove date related texts from images

From GOGREEN-812
"In general, the content must be such that we can update "just" the metadata to make this work. The texts, and images, should not contain any dates so this is a repeatable process that just needs scripting. "

Identified images that have dates or other problematic issues (in trunk):
/content/gallery/events/2014/05/Sustainability NF brochure.jpg
/content/gallery/events/2014/08/SEBC.png
/content/gallery/events/2014/08/biofuelslogo.png
/content/gallery/events/2014/11/bioexpo-logo-2.png
/content/gallery/events/2014/09/inter2010.jpg [date without year]
/content/gallery/events/2014/09/globalsustainable.png
/content/gallery/events/2014/10/watersmart.png
/content/gallery/events/2014/10/Untitled-1-012-927x1024.png [timeschedule]
/content/gallery/events/2014/10/Untitled-2-01-1024x305.png [table with content]
/content/gallery/events/2014/12/nextgenfuels.png