Remove hack to disable bytecode writing

If the user wants it for some reason, he can set the environment
variable or use -B. This line forced the choice with no way to
circumvent it.
This would break packaging systems such as Gentoo's distutils-r1.
Tabs to spaces
Hack to force the inclusion of chardet2

when building sdist with python2.
Merge pull request #2 from laurentb/master

Various packaging fixes