powerline: Remove unnecessary test dependencies

Now powerline tests try to import bzrlib or mercurial packages and use the
result (either success or ImportError) to determine whether appropriate tests
should be run. Not the case for git.
powerline: Add 1.0 release
powerline: Remove all keywords from live ebuild
powerline: Use ${S} in 9999 ebuild as well
powerline: Fix 9999 header
powerline-python: Fix 9999 header
powerline-python: Fix indentation
powerline-python: Use ${S} where appropriate
powerline-python: Fix sed call

Option `-i` *accepts an argument*. So what is present here is not `sed -i -e …`,
it is `sed --in-place=e …`.
powerline-python: Add 1.0 release