Merge pull request #57 from kyoushuu/master

Various fixes in resources, songs view and playback
grilo: Create a default options object and use a copy on populate

This will decrease the memory usage when loading views.
widgets: Use set_label method to set load more button label
Merge pull request #67 from kyoushuu/load-more-button-label

Use set_label method to set load more button label
Merge pull request #68 from kyoushuu/grilo-options-profile

Create a default grilo options object and use a copy on populate
player: Skip unplayable tracks