[MRG+1] Handle relative sitemap URLs in robots.txt

[MRG+1] Fix #396 re-triggered issue

[MRG+1] Print more dependencies versions in "scrapy version" verbose output

The InteractiveShellEmbed class is a singleton
and we need to drop the instance with its clear_instance() method
to rebuild the instance from scratch with fresh environment
for each subsequent Scrapy's shell drop in.

[MRG] DOC Remove "Ubuntu" section from sidebar/ToC

As described in http://www.sphinx-doc.org/en/latest/markup/misc.html#metadata

[MRG+1] Add middleware to template project (closes #2335)

[MRG+1] Document `download_latency` meta key

[MRG+1] LinkExtractor PY3 'unicode' type fix

[MRG+1] Add better messages for when response content isn't text (closes #2264)

[MRG+1] Update conda channel to conda-forge and show conda version badge.

Test Slot's heartbeat state before stopping it

Also add a test on state of looping task in LogStats extension

Fixes #2011 and #2362

Document update in "Using Firefox for scraping"

Fix typo in media pipeline docs

[MRG+1] Update documentation to explain the use of double quotes on Windows (fixes #2325)

[MRG+1] doc: wording

Fix tutorial AuthorSpider

Thx for your advice.

In the AuthorSpider, original css selector failed to get links of author pages

Update release notes for upcoming 1.2.1

Typo (through was misspelled)