Handle Cloudsearch Indexing Errors

Previously the code handled errors on individual items but not an error response that included no 'adds' or 'deletes' keys resulting in a KeyError
Added test for cloudsearch indexing errors
Remove mock from Python 3 requirements.
Add dynamodb2 to whitelist
Remove code for Python 2.5 compatibility.
Fix __nonzero__ => __bool__
Fix some tests.
Merge remote-tracking branch 'origin/develop' into dynamo2-py3

Conflicts:
	boto/dynamodb/types.py
	tests/test.py
Fix tests.
Treat bytes as binary type on Python 3.
Fix integration tests.
Fix integration tests.
Update README
Prevent an infinite loop.

Fixes the issue observed in the Google Storage integration tests
from #2462. The problem was introduced in f3e5d11. This only uses
the internal cached value instead of potentially triggering infinite
list bucket calls.
Fix S3 integ test on Py3
[DOC] Fixed #2464 added keyword "detailed"
Loading binary from dynamodb returns dynamodb.types.Binary.
Fix tests.
remove obsolete md5 import routine

The old md5 module was deprecated since Python 2.5, and we even didn't
support that version already. The current implementation in
boto/utils.py will not even work under Python 2.4 because of the name
"md5" imported from md5 module was replaced by the md5 module in the
following routine, which will cause errors.
Updated documentation for copy_image