Tweak build configuration.
Npgsql2013.sln -> NpgsqlDdexProvider2013.csproj
- off Debug-net20
- off Debug-net35
- off Debug-net40
- on Debug-net45
- on Debug-net45-ef6
- off Release-net20
- off Release-net35
- off Release-net40
- on Release-net45
- on Release-net45-ef6