add NuGet.Services.Search.Comparer project for testing target framework related changes
Tests verified by running
minor update
fix typos
process the excluded project types
Merge pull request #29 from NuGet/danliu/tftests

Danliu/tftests
added framework compatibility filter
Merge branch 'master' of https://github.com/NuGet/NuGet.Services.Search into sblom/targetfx-collector
Merge branch 'sblom/targetfx-collector' of https://github.com/NuGet/NuGet.Services.Search into sblom/targetfx-collector