protobuf-net 2.0.0.668

* 2.0.0.668 - fix: reader's position not resetting: eventually causes overflow on pooled instance; critical fix to 663 * 2.0.0.666 - add: Support for BCL immutable types (Microsoft.Bcl.Immutable) * 2.0.0.664 - add: Remove some more allocations (IPredicate) * 2.0.0.663 - add: ProtoReader recycling for heavy read throughput - add: precompile uses alternative switch construct (android limitations) * 2.0.0.651 - add: new key-signing options for precompile - add: enum-passthru defaults * 2.0.0.640 - fix: bug with length-prefix / naked enumerations * 2.0.0.638 - update: protoc 2.5 - fix: various tweaks for Genderme - fix: better support for "naked enumerables" (root enumerable objects) * 2.0.0.627 - fix: bug in "precompiler" for lots of types - add: support for default type factories (including extended callback signature support) - fix: ImplicitFields parsing failing if assembly loaded dynamically - add: experimental support for concurrent collections - add: support for tuples with AsReference; better handling of default AsReference; improved AsReference error message * 2.0.0.622 - fix: bug in protogen with default enums when no package is specified * 2.0.0.621 - fix: nasty regression in r619, where GetSchema() could cause base-type corruption * 2.0.0.619 - fix: GetSchema() should use ultimate base-type names when modelling inheritance - fix: ensure precomile always generates a .ctor() on the concrete serializer - add: support out-of-order fields when deseiralizing inheritance from other protobuf implementations * 2.0.0.614 - fix: enum handling of ": byte" confusing signed/unsigned bytes * 2.0.0.612 - fix: allow adding enum maps at runtime via MetaType * 2.0.0.611 - fix: *Specified should work with non-public methods - performance: pre-compiled serializers now use dictionary lookups where appropriate - fix: nuget package for portable library should be more inclusive * 2.0.0.602 - added precompiler support for internal-types and [InternalsVisibleTo(...)]-forwarding - made AllowParseableTypes available on default type-model * 2.0.0.601 - added phone8 support