Install the Python binding via pip

[mayataka]

The current install procedure of the Python binding is inconvenient.
It would be nice if we can install it through pip, .e.g, by pip install . --user.
An install script (setup.py or something like that) that satisfies

• Builds and installs C++ shared library as well as Python binding
• Enables CMake options (-DOPTIMIZE_FOR_NATIVE and -DBUILD_VIEWER)

is desired.