Unfork Base64Coder, add upstream as maven dep

I'm trying to get openshift-java-client into Fedora (mainly for jbosstools-openshift). One of the issues raised in the initial package review[0] is that base64coder is forked here, which goes against our guidelines.

The only difference between the upstream maven dependency and the com.openshift.client.utils.Base64Coder version, is basically the upstream commit at [1]. I don't know how important this difference might be, or if it's important, why it never got released upstream.

There may be things changed in this commit - I'm not 100% familiar with maven yet. It builds for me though, and all tests pass. Let me know if you would like me to change anything :)

[0] https://bugzilla.redhat.com/show_bug.cgi?id=902017
[1] http://svn.source-code.biz/viewvc/base64coder-java/trunk/src/main/java/biz/source_code/base64Coder/Base64Coder.java?r1=13&r2=19