clenaup: remove commented out code
build: 0.0.6-1
[copr] correctly specify chroot when it should be guessed

previously chroot would contain just release version (e.g 20)
also expand it to several lines which is more readable then cryptic one liner
tests: fix locale independence.
noroot: move to the new 'demands' mechanism to check the need of root.

Needs new DNF.

Related: RhBug:1062889
refactor: command plugins use demands mechanism.

See dnf commit 8830a1c.
fix resource leak in builddep.py.

Note that contextlib.ContextDecorator is not available in py2.
kickstart: use new public Command.usage & Command.summary api
builddep: added usage & summary & fix some PEP8 issues