Merge pull request #589 from sporty81/master

when tracing is enabled, log the actual json request
optimize access to dictionary
Tests to prove #606
extremely wordy unit test name. Forgot to change to correct expectation
[Tidy up] Moved test into fields integration test folder
Fix #606 and #607, also improved API around a great deal by exposing a .FieldSelections propery on SearchResult wich does the hard part of typing the propery accessor for you
Merge pull request #619 from elasticsearch/fix/dynamic-search-results

This change improves the usability around Fields