Include more context information if BuildSerializer fails

git-svn-id: http://protobuf-net.googlecode.com/svn/trunk@652 b72047a4-3652-0410-9617-b3994939e97b
multi-switch for large switch statements (> 128 branches)

git-svn-id: http://protobuf-net.googlecode.com/svn/trunk@653 b72047a4-3652-0410-9617-b3994939e97b
When is a Type not a Type?

git-svn-id: http://protobuf-net.googlecode.com/svn/trunk@654 b72047a4-3652-0410-9617-b3994939e97b