replace dumb printf-style syntax with str.format

Signed-off-by: Kwpolska <kwpolska@gmail.com>
implement the doit command interface in the command plugins
use doit commands from the nikola script
ported to doit commands
better doc
fix doc
removed build (not needed anymore), ported bootswatch
ported check command
ported console command
ported import_blogger
ported import wordpress command
more command porting
ported new_post
use the right doc_
add undocumented option
updated changelog
flake8
Update nikola/plugins/command_check.py
typo

Signed-off-by: Kwpolska <kwpolska@gmail.com>
Merge branch 'better-errors-no-percent' of github.com:Kwpolska/nikola into better-errors-no-percent