Fix indentation

Fix indentation

I've noticed that a bunch of the code we've included over the past few
weeks has been using 8-spaces rather than tabs, making it all very hard
to read depending on your tabstop setting.

This commit attempts to revert all of that back to proper tabs and fix a
few more cases I've noticed here and there.

No functional changes are included in this commit.

Signed-off-by: Stéphane Graber <stgraber@ubuntu.com>