use another hash function if MD5 is not available
Fix a rare NPE crash in Android 2.x
See http://crashes.to/s/5ee30776a5d
Merge pull request #216 from robUx4/npe_android2x

Fix a rare NPE crash in Android 2.x
Merge pull request #215 from robUx4/missing_md5_workaround

use another hash function if MD5 is not available
Some HTTP servers are sending only newline instead of CRLF.
Merge branch 'master' into spdy

Conflicts:
	AndroidAsync/src/com/koushikdutta/async/http/AsyncHttpResponseImpl.java