Upstream protobuf removed scoped_ptr.h, which provided the scoped_ptr
that we depended on, in commit 67952fab2c766ac5eacc15bb78e5af4039a3d398
(67952fab2c).
This commit converts uses of scoped_ptr type to idiomatic C++11
std::unique_ptr, similar to the changes in the protobuf commit.
This has been tested on protobuf 3.0.0 (the version currently in Debian)
as well as the latest protobuf 3.6.1 release.
per https://code.google.com/p/protobuf/source/detail?r=50, the license
on google-originated protobuf code was switched from Apache-2.0 to
BSD-3-Clause (so-called "New BSD" license). update any of the google
license statements to use this new license.
per email with dave, drop the third clause on his BSD-3-Clause license,
so this now becomes BSD-2-Clause.
make sure to use consistent indentation and wrapping throughout.
