replace dumb printf-style syntax with str.format

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

Signed-off-by: Kwpolska <kwpolska@gmail.com>

Conflicts (already resolved):
	nikola/plugin_categories.py
	nikola/plugins/command_bootswatch_theme.py
	nikola/plugins/command_build.py
	nikola/plugins/command_check.py
	nikola/plugins/command_deploy.py
	nikola/plugins/command_import_blogger.py
	nikola/plugins/command_install_theme.py
	nikola/plugins/command_new_post.py
	nikola/plugins/command_serve.py
	nikola/plugins/task_redirect.py
missed this one

Signed-off-by: Kwpolska <kwpolska@gmail.com>
Python 3.3 exists since a long while

Signed-off-by: Kwpolska <kwpolska@gmail.com>
Merge pull request #330 from Kwpolska/master

Add Python 3.3 to the Travis tests
Merge pull request #326 from Kwpolska/better-errors-no-percent

Make errors more informative; replace dumb printf-style syntax with not-so-new str.format() hotness
Introducing self-created meta fields.

Signed-off-by: Kwpolska <kwpolska@gmail.com>
META NOW WORKS!

Signed-off-by: Kwpolska <kwpolska@gmail.com>
self-meta: more than 15 fields supported

Signed-off-by: Kwpolska <kwpolska@gmail.com>
bugfixes + tests changed to use new get_meta output format

Signed-off-by: Kwpolska <kwpolska@gmail.com>
should fix the self-meta

Signed-off-by: Kwpolska <kwpolska@gmail.com>
fixed formatting (via #326)

Signed-off-by: Kwpolska <kwpolska@gmail.com>
oops…

Signed-off-by: Kwpolska <kwpolska@gmail.com>
Travis chokes on those, so let’s try fixing them.

Signed-off-by: Kwpolska <kwpolska@gmail.com>
All tests pass!

Signed-off-by: Kwpolska <kwpolska@gmail.com>
Run nikola with help argument. Running without an argument results in an error (but with exit code 0).
Running flake8.