Moves add_papers fonctionality.

Now:
- paper.py provides extraction of many Papers from bib,
- command performs the loop to add each paper to repo.

papers/commands/add_library_cmd.py

@@ -1,4 +1,5 @@
 from .. import repo
+from ..paper import Paper
 
 
 def parser(subparsers, config):
@@ -7,9 +8,11 @@ def parser(subparsers, config):
     parser.add_argument('bibfile', help='bibtex, bibtexml or bibyaml file')
     return parser
 
+
 def command(config, bibfile):
     """
     :param bibtex       bibtex file (in .bib, .bibml or .yaml format.
     """
     rp = repo.Repository.from_directory()
-    rp.add_papers(bibfile)
+    for p in Paper.many_from_bib(bibfile):
+        rp.add_paper(p)

papers/paper.py

@@ -146,3 +146,9 @@ class Paper(object):
     @classmethod
     def create_meta(cls):
         return BASE_META.copy()
+
+    @classmethod
+    def many_from_bib(cls, bibpath):
+        bib_data = files.load_externalbibfile(bibpath)
+        return [Paper(bibentry=bib_data.entries[k], citekey=k)
+                for k in bib_data.entries]

papers/repo.py

@@ -91,13 +91,6 @@ class Repository(object):
         paper.save_to_disc(self.path_to_paper_file(paper.citekey, 'bib'),
                 self.path_to_paper_file(paper.citekey, 'meta'))
 
-    def add_papers(self, bibpath):
-        bib_data = files.load_externalbibfile(bibpath)
-        for k in bib_data.entries:
-            sub_bib = bib_data.entries[k]
-            p = Paper(bibentry=sub_bib, citekey=k)
-            self.add_paper(p)
-
     def get_free_citekey(self, paper, citekey=None):
         """Create a unique citekey for the given paper.
         """