[grilo-plugins] tracker: add support for composer key

[Bastien Nocera <hadess src gnome org>]

commit 58c1105fcae0fec8c98c7e744de6f774fa826d64
Author: fosero <fosero users noreply github com>
Date:   Mon Feb 8 00:14:22 2016 +0100

    tracker: add support for composer key
    
    Add support for GRL_METADATA_KEY_COMPOSER
    
    https://bugzilla.gnome.org/show_bug.cgi?id=761624

 src/tracker/grl-tracker-utils.c |    5 +++++
 1 files changed, 5 insertions(+), 0 deletions(-)
---
diff --git a/src/tracker/grl-tracker-utils.c b/src/tracker/grl-tracker-utils.c
index be3b36d..fd3e438 100644
--- a/src/tracker/grl-tracker-utils.c
+++ b/src/tracker/grl-tracker-utils.c
@@ -224,6 +224,11 @@ grl_tracker_setup_key_mappings (void)
                       "nfo:entryCounter(?urn)",
                       "directory");
 
+  insert_key_mapping (GRL_METADATA_KEY_COMPOSER,
+                      NULL,
+                      "nmm:artistName(nmm:composer(?urn))",
+                      "audio");
+
   insert_key_mapping (GRL_METADATA_KEY_SIZE,
                       NULL,
                       "nfo:fileSize(?urn)",