Streamline tutorial docs

Fixes #634 
Replaces repetitive tutorials with an "Examples" section in "Getting Started", with much simplified structure and tutorials replaced with more minimal example Flocker config files and instructions.
Ach, must've been merged in to master after I branched off to create this branch. Are you aware of any substantive changes now in master against these docs? I doubt I'm going to get away with trying to merge a branch that changed any of these original tutorials in to this one, so I'll probably have to manually transpose the changes. I don't want to see alt text or anything else getting lost.