fix logging error with unicode spider name

Log message fails if spider name is in unicode, because "system" key in eventDict isn't encoded.
Update CrawlSpider Template with Selector changes
Merge pull request #484 from nyov/nyov/crawl-tmpl-selector

Update CrawlSpider Template with Selector changes
Add 0.20.2 release notes

Conflicts:
	docs/news.rst
Note about selector class import

This is the salient point of this code compared to the last example.  We have a selector now and this is how we use it.  Especially since the user has just come from the shell where the pre-instantiated selector is taken for granted.
Merge pull request #489 from RasPat1/patch-2

Note about selector class import
add new pipeline methods to get file/image/thumbnail paths

This change allows to pass request, response and spider context to filename
construction methods.
add deprecation warnings for old file_key/image_key/thumb_key methods
better marker name to detect overridden methods
simplify porting to Python 3
switch existing pipeline tests to use new file_path/image_path methods
rename key to path in FilesPipelineTestCase
rename FilesPipelineTestCase image_path var to file_path for clarity
implement DeprecatedFilesPipelineTestCase
implement DeprecatedImagesPipelineTestCase
rename ImagesPipelineTestCase image_path var to file_path for clarity
test for new response and info keyword arguments
fix missing keyword arguments for file_path in media_downloaded()
add distutils folders to gitignore
Merge pull request #479 from citizen-stig/unicode_spider_name

fix logging error with unicode spider name