SearchRepo should return POCO instead of collection

[shiftkey]

As part of resolving #411 we need to do a bit of work to deserialize things properly.

This is what we get from the server:

{
  "total_count": 40,
  "items": [
    {

    }
  ]
}

I thought about whether we could bypass all this and check for the presence of items in the JSON - perhaps we don't care about total_count - but the magic for that is deep inside Connection.

This PR fixes the SearchRepo method the user has report, but the other search methods need to be addressed as well.

• add integration test and fix problem
• update impacted tests
• we should return a read-only collection - this isn't working in SimpleJson (how are we doing with updating that @haacked?)

Fixes #411

[shiftkey]

Removed [WIP] tag, ready for review

[haacked]

Heh, I just noticed our intermediate path is still Net40. Doesn't matter, but it's odd. 😄

[haacked]

Nice work @shiftkey!

[haacked]

Whoops, forgot to choose an emoji. 🌠 ✌️