Rewrote protobuf varint read methods. Don't go through string representations first.
Also rewrote encoding part of protobuf varints.
Revert "Also rewrote encoding part of protobuf varints."

This reverts commit 7b30c0602b18254960d097de60714b7db1c36f5e.
Fix handling of negative numbers in set_value() (we do not use those though)
Remove newline