BaseSgmlLinkExtractor: Fixed unknown_endtag() so that it only set current_link=None when the end tag match the opening tag
BaseSgmlLinkExtractor: Added unit test of a link with an inner tag
BaseSgmlLinkExtractor: Fixed the missing space when the link has an inner tag
Make Filesystem storage backend default again. See GH-500.
Merge pull request #541 from kmike/fs-as-default-cache

[MRG] Make Filesystem storage backend default again.
Merge 0.22.0 release notes
bump version to 0.23
Disable smart strings in lxml XPath evaluations
Make lxml smart strings functionality customizable
Add testcase to check is default Selector doesnt return smart strings
fix typos in news.rst and remove (not released yet) header
fix 0.22.0 release date
modify the version of scrapy ubuntu package

latest version is 0.22.
with scrapy-0.18, tutorial project provides error
relative issue : https://github.com/scrapy/scrapy/issues/511
Update Ubuntu installation instructions
Use assertTrue/False
fix apt-get line
replace warning about updating package lists by a note on package upgrade
Merge pull request #549 from dangra/509-scrapy-apt-repo

[MRG] update instruction to install using ubuntu packages
show ubuntu setup instructions as literal code
Merge pull request #535 from redapple/xpath-smartstrings

Disable smart strings in lxml XPath evaluations