Hey,

some support for GOA in flickr plugin would be nice, wouldn't be?
It definetily would, so here it is.

I added two optional features (during compilation): --enable-flickr-goa-forced and --enable-flickr-goa.
The forced thing means that plugin will take configuration only from GOA and any other configuration passed is ignored. (So with no GOA flickr account plugin initiation fails)
The --enable-flickr-goa option behaves the old way (takes programmer's configuration and goes through it) but if boolean "flickr-enable-goa" is found in configuration and it's TRUE, then it tries to take configuration from GOA either. So using this option the only thing needed to allow plugin search in GOA is write this line into configuration:
grl_config_set_boolean (config, "flickr-enable-goa", TRUE);
This option was marked default in configure.ac

When creating this patch I used source codes after patching to OAuth patch (https://bugzilla.gnome.org/show_bug.cgi?id=697175) because it searches for OAuth keys in GOA.