Added build script for benchmark.

Signed-off-by: FrankHB <frankhb1989@gmail.com>
Simplified type declarations.

Signed-off-by: FrankHB <frankhb1989@gmail.com>
Simplified implementation: Used duration directly and reduced the default test time limit.
benchmark/benchmark.cpp: Removed file output, simplified and fixed return value type.

Signed-off-by: FrankHB <frankhb1989@gmail.com>
benchmark/benchmark.hpp: Used YSLib to simplify implementation.

Signed-off-by: FrankHB <frankhb1989@gmail.com>