Fix #4: Incorporate Java Conding Style

Add IntelliJ coding style files based on Google coding style.
Fix #134: Add travis-notification via gitter
Fix #12: Fix attachments additional props handling
Fix #42: NTLM Auth by by upgrading HttpClient

Upgrade HttpClient from 3.1 to 4.3.5
Add explicit depedendency on HttpCore 4.3.3
Readme for dealing with Autodiscover redirection

contains some example code in implementing the RedirectionCallback which
came from looking at:

http://msdn.microsoft.com/en-us/library/office/dd635285%28v=exchg.80%29.aspx
Fix #30: Convert.ToBase64String() invalid encoding

removed Convert.java because (I think it is dangerous and should not be used)
used org.apache.commons.codec.binary.Base64 instead
added test
Fix #4: Reformat code based on coding conventions

- Optimize imports
- Reformat code based on coding conventions.