Update httperror.py

Log ignored HTTP pages when the response code is not allowed or not configured to be handled.
Update scrapy command line doc with additional scrapy parse options
remove unused setting: DOWNLOADER_DEBUG
Added missing word in practices.rst
Clarify MapCompose documentation
Fix some typos, whitespace and small errors in docs
Merge pull request #618 from allait/master

Fix some small typos and errors in docs
Generalize the file pipeline log messages so they are not specific to downloading images.
Merge pull request #622 from ajw0100/generalize-file-pipeline-log-messages

Generalize the file pipeline log messages
SpiderMW doc typo: SWP request, response
Running lucasdemarchi/codespell to fix typos in docs
Running lucasdemarchi/codespell to fix typos in SEPs
Running lucasdemarchi/codespell to fix typos in code
Merge pull request #628 from barraponto/codespell

Using lucasdemarchi/codespell to fix typos
Converted sep-001 to rst format
converted sep 002 to rst
- decided that removing files would cause conflicts on merge
- readded file to prevent future merge conflicts
converted sep 3 for #629
sep 4 for #629