Merge master into security-vuln-patches
Merge pull request #1946 from jekyll/security-vuln-patches
Update history to reflect merge of #1946 [ci skip]
Make the layouts: config key relative to CWD or to Source

Fixes #1576.
Add tests for determining source dir
Update license with all years since 2008.

Closes #2059.
:fire: permalink option so default date permalink method is left in tact
Merge pull request #2041 from anthonyjsmith/webrick_index_xml
Update history to reflect merge of #2041 [ci skip]
Adds mobile styling for menu at sub 600px viewport widths
Replace unicode menu icon with inline SVG

- unicode menu icon doesn’t render pixel crisp (has some
anti-aliasing), whereas SVG renders pixel optimized
- using inline SVG (instead of a referenced, attached file, will save
an http request
Post content styles for mobile
Replace footer github and twitter link text with inline SVG icons
Make LayoutReader#layout_directory public.

Since it's being used in a test, let's go ahead and expose it instead of
dealing with using Object#send to send the message along.
Add clarification about output path of asset files
Merge pull request #2058 from jekyll/layouts-relative-to-config
Update history to reflect merge of #2058 [ci skip]
Move Kramdown version bump to Minor Enhancements section.

Closes #2069.
[configuration.md] Correct typo

Typo: 'use'
Proposed Correction: 'uses the'
---
In English, 'use' is the verb form for plural subjects, where as 'uses' is the verb form for a singular subject. For this case, the subject, 'default value', is singular.
Merge pull request #2073 from mizuhands/patch-1