More email package fixes.

MIMEApplication() requires a bytes object for its _data, so fix the tests.

We no longer need utils._identity() or utils._bdecode().  The former isn't
used anywhere AFAICT (where's "make test's" lint? <wink>) and the latter is a
kludge that is eliminated by base64.b64encode().

Current status: 5F/5E
diff --git a/Lib/email/encoders.py b/Lib/email/encoders.py
index 06016cd..2e77e61 100644
--- a/Lib/email/encoders.py
+++ b/Lib/email/encoders.py
@@ -11,8 +11,8 @@
     'encode_quopri',
     ]
 
-import base64
 
+from base64 import b64encode as _bencode
 from quopri import encodestring as _encodestring
 
 
@@ -23,19 +23,6 @@
     return enc.replace(' ', '=20')
 
 
-def _bencode(s):
-    # We can't quite use base64.encodestring() since it tacks on a "courtesy
-    # newline".  Blech!
-    if not s:
-        return s
-    hasnewline = (s[-1] == '\n')
-    value = base64.encodestring(s)
-    if not hasnewline and value[-1] == '\n':
-        return value[:-1]
-    return value
-
-
-
 def encode_base64(msg):
     """Encode the message's payload in Base64.