Improvements on the documentation

* Remove duplicated specs.
* Make the docs to include the type specs defined in .hrl files.
* Change the documentation to reflect all the changes that were lately done to the library.
Use a nicer style for the edocs

Taken from https://github.com/basho/riaknostic/blob/develop/priv/edoc.css
Fix type errors. Remove unused functions. Fix documentation
Add a better README file
Update the copyright lines
Remove old files not needed anymore

Now we are using Rebar to build.
Small additions to the Readme.md