Possible fix for unicode errors with non ascii path.

src/libprs500/library/database.py

@@ -36,6 +36,8 @@ class Concatenate(object):
         return self.ans
 
 def _connect(path):
+    if isinstance(path, unicode):
+        path = path.encode('utf-8')
     conn =  sqlite.connect(path, detect_types=sqlite.PARSE_DECLTYPES|sqlite.PARSE_COLNAMES)
     conn.row_factory = lambda cursor, row : list(row)
     conn.create_aggregate('concat', 1, Concatenate)