Support bugs filed against src:foo

Signed-off-by: Adam D. Barratt <adam@adam-barratt.org.uk>

Currently a bug against src:foo is treated as if it were filed against
foo.  As both may exist in the input list, we accumulate bugs for each
package rather than assuming package names are unique.

britney.py

@@ -566,7 +566,10 @@ class Britney:
             if len(l) != 2:
                 print "WARNING: Malformed line found in %s: %s" % (file, line)
                 continue
-            bugs[l[0]] = l[1].split(",")
+            pkg = l[0]
+            if pkg.startswith('src:'): pkg = pkg[4:]
+            bugs.setdefault(pkg, [])
+            bugs[pkg] += l[1].split(",")
         return bugs
 
     def write_bugs(self, basedir, bugs):