Fix #697
updated pt_br translation
6.0.2 because f*ck it
Addresses several issues in #704

- Avoids shell=True and hence any quoting issues
- Cleans up temporary directory

This code has not been run since FILTERS don't appear to be tested.
Don't bother creating temp directory unless it is needed
Typo (Fix #706)
Merge pull request #707 from rogerbinns/issue-705

Addresses several issues in #705
updated changelog
flake8 fixes
Fix #708
fixed conflict
Handle part of #551
Fail better if PIL fails (Issue #551)
Raise awareness of filters

Signed-off-by: Chris “Kwpolska” Warrick <kwpolska@gmail.com>
webassets was missing from requirements-full.txt
Fix #551
Merge branch 'master' of github.com:getnikola/nikola
merged master
Merge pull request #698 from getnikola/empty-conf

Fix #697
oops