Using $(maven_coords :target) marco

Note: This this macro is not yet available on buck master

Also, simplifying app/fwd buck file and improving onos_app
readability by using feature_coords instead of feature_name

Change-Id: I9aff07d66331a537f6711bf15fd760cf910f1afc
diff --git a/buck-tools/onos_app.py b/buck-tools/onos_app.py
index ab2dfc6..89c4252 100755
--- a/buck-tools/onos_app.py
+++ b/buck-tools/onos_app.py
@@ -96,7 +96,7 @@
     import sys, optparse
 
     parser = optparse.OptionParser()
-    parser.add_option("-n", "--name",     dest="feature_name", help="Feature Name")
+    parser.add_option("-n", "--name",     dest="feature_coords", help="Feature MVN Coords")
     parser.add_option("-a", "--app",      dest="app_name",     help="App Name")
     parser.add_option("-o", "--origin",   dest="origin",       help="Origin")
     parser.add_option("-c", "--category", dest="category",     help="Category")
@@ -124,8 +124,8 @@
     (options, args) = parser.parse_args()
 
     values = {}
-    if options.feature_name and options.version and options.title:
-        values['feature_name'] = options.feature_name.split(':')[1]
+    if options.feature_coords and options.version and options.title:
+        values['feature_name'] = options.feature_coords.split(':')[1]
         values['version'] = options.version
         values['title'] = options.title
     else:
@@ -144,7 +144,7 @@
         sys.exit(1)
 
     values['feature_repo_name'] = options.repo_name if options.repo_name \
-                                    else options.feature_name
+                                    else options.feature_coords
 
     if options.write_features:
         bundles = []