Pass around a Search ID

[aluhrs13]

To be able to go from:

• User searched for foo
• User viewed N Minis
• User left site for a Mini

Todo List:

• Generate a unique ID on search
• Pass ID between pages
• Pass ID to /Minis/Details
• Pass ID to /Minis/Redirect
• Add ID to ViewedMini
• Add ID to MiniRedirect
• Make a funnel