Placeholder can be output when no sfImagePoolImage found
Placeholder can be output when no sfImagePoolImage found

If the passed object to pool_image_uri() has no image objects assigned,
nothing was output before. Now, if the placeholders option is true, a
placeholder will be output.

HollerLondon/sfImagePoolPlugin,HollerLondon/sfImagePoolPlugin,HollerLondon/sfImagePoolPlugin