* Fix type conversion warnings.
Fixes#949
Tested locally (Linux/clang), but warnings are on MSVC so may differ.
* Drop the ULP so the double test passes
* format all documents according to contributor guidelines and specifications
use clang-format on/off to stop formatting when it makes excessively poor decisions
* format all tests as well, and mark blocks which change too much
* Allow AddRange to work with int64_t.
Fixes#516
Also, tweak how we manage per-test build needs, and create a standard
_gtest suffix for googletest to differentiate from non-googletest tests.
I also ran clang-format on the files that I changed (but not the
benchmark include or main src as they have too many clang-format
issues).
* Add benchmark_gtest to cmake
* Set(Items|Bytes)Processed now take int64_t
