Prep for rc4 release.

This commit changes the layout of the doc site to better suit multiple versions and components.

The expected release process in the future is as follows:
 
# To release:

API docs
========
Add API docs for mapreduce and schema to apidocs/kiji-*/1.0.0-rc*
Add updated docs for annotations, hbase-maven plugin, hadoop-configurator, and kiji-delegation.
Update the "latest" links in apidocs/index.md

Tutorial
========
Check the client tests of tutorial pass. If so, release!

UserGuide
=========
Hope that it is up to date.

# To prep for next release:

API Docs
========
Nothing for now.

Tutorials
=========
For each component, copy the directory of most recent version into a new dir with the version incremented.
  eg:
    mkdir _posts/tutorials/phonebook-tutorial/1.0.0-rc5
    cp _posts/tutorials/phonebook-tutorial/1.0.0-rc4/* _posts/tutorials/phonebook-tutorial/1.0.0-rc5
Update the links in tutorials.md (in root dir of project)

UserGuide
=========
For each component, copy the directory of most recent version into a new dir with the version incremented.
  eg:
    mkdir _posts/userguides/kiji-schema/1.0.0-rc5
    cp _posts/userguides/kiji-schema/1.0.0-rc4/* _posts/userguides/kiji-schema/1.0.0-rc5
Update the links in userguides.md (in root dir of project)