Merge branch 'master' into handle-categories-in-site-config-defaults
Set categor[y|ies] on post if they appear in site frontmatter defaults
Accept Numeric values for dates.
Add collections to info about pagination support.

Currently: _Pagination does not support tags or categories_
Proposed: _Pagination does not support tags, categories or collections_

Maybe in the future? Related: #2376
Adding to pagination note: Cannot include collections

Adding a sentence to the paragraph to clarify, that pagination is restricted to posts and that it can't contain collections.
Allow subdirectories in _data
Add _data sub-folder support to docs
Add scenario for ensuring data folder over file precedence
Fix #2413 and setup a Jekyll.env.
date_to_xmlschema does some weird things with timezones, but whatever it's not important.
Merge pull request #2377 from jekyll/numeric
Update history to reflect merge of #2377 [ci skip]
Add jekyll.environment to site_payload.
Add test for Jekyll.env
Merge pull request #2417 from jekyll/jekyll-env
Update history to reflect merge of #2417 [ci skip]
Override collection url template
Encode URLs in utf-8 when escaping and unescaping

There is a problem while returning a path that has some special and possible Non-ASCII characters that may lead jekyll to break while doing the unescaping process. This is can be addressed by “forcing” ASCII to UTF-8.
Fix broken link on installation.md
Merge pull request #2421 from chezou/fix-broken-link