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
Ignore None's values when using the ItemLoader.
Unused re import and PEP8 minor edits.
Expose current crawler in the scrapy shell.
PEP8 minor edits.
Updated shell docs with the crawler reference and fixed the actual shell output.

Also updated the shell example with a reproducible code example.
Updated the tutorial crawl output with latest output.
Merge pull request #556 from darkrho/item-loader-nones

Make `ItemLoader` ignore `None` values from processors.
Merge pull request #557 from darkrho/expose-crawler-in-shell

Expose current crawler in the scrapy shell.
Merge pull request #565 from dangra/562-sgmlinkextractor

replace unencodeable codepoints with html entities
Offsite: add 2 stats counters
Always enable offsite stats + refactor test to initialize crawler
DOC Fixed HTTPCACHE_STORAGE typo in the default value which is now Filesystem instead Dbm.
Merge pull request #571 from darkrho/httpcache-storage-doc

DOC Fixed HTTPCACHE_STORAGE typo in the default value which is now Files...
Fix tests for Travis-CI build
Merge pull request #570 from redapple/travistests

[MRG] Fix tests for Travis-CI build
Merge pull request #566 from redapple/offsite-stats

OffsiteMiddleware: add 2 stats counters
Merge pull request #485 from bblanchon/sgml-extractor-link-text

SgmlLinkExtractor: Fixed link text when there is an inner tag