Please add variables that control docs and examples install

[yurivict]

In the FreeBSD port we only need to install docs and examples when corresponding port options are chosen.
Currently, we have to patch setup.py to achieve this.
It would have been much nicer if corresponding build variables could be passed to setup.py.

[meejah]

Hi. I'm definitely not opposed to making those things optional -- is there already a 'standard' way to do this with setuptools / setup.py that would work for your use-case?

[yurivict]

I am not sure if there is a standard way.
You can do --enable-docs/--disable-docs and --enable-examples/--disable-examples.