cards.py: Add generic function to read EF record in card class

This is a generic function applicable for reading EF records which doesnt require further processing
such EF.SMSP etc while decoding and also to avoid code duplication.

Change-Id: Ic0b4aa11e962b4bb328447b11533136a29ff72d3
diff --git a/pySim/cards.py b/pySim/cards.py
index 7d3b7b4..c702608 100644
--- a/pySim/cards.py
+++ b/pySim/cards.py
@@ -149,6 +149,10 @@
 		ef_path = ef in EF and EF[ef] or ef
 		return self._scc.read_binary(ef_path, length, offset)
 
+	def read_record(self, ef, rec_no):
+		ef_path = ef in EF and EF[ef] or ef
+		return self._scc.read_record(ef_path, rec_no)
+
 	def read_gid1(self):
 		(res, sw) = self._scc.read_binary(EF['GID1'])
 		if sw == '9000':