provide handlers for the Audio: Player link/flash for all players

Today I added a small block to my site with a view that had a single audio node. I wanted all pages on the site to show the most recent podcast on the site. However, while the 1pixelout player works best for my teasers and nodes, I'd really rather have the XSPFbutton in the sidebar due to the way that the 1pixelout player expands beyond the width of my sidebar.

The attached patch provides this feature by adding several more handler functions for the "Audio: Player link/flash" field. These extra functions call a modified version of audio_get_node_player with a specific (though optional) $type. The updated function audio_get_node_player($node, $type = NULL) {
will use the right player for the situation for backwards compatibility, but will use a specific player as requested in the optional second function argument.