Minor performance fix to not double-compute metadata in directory_indexes.
Simplify frontmatter by removing its resource_list_manipulator
Fix a bunch of Ruby warnings, including a bug in the not_found method
Overhaul content-type handling, making it configurable via page/proxy commands as well as frontmatter with the 'content_type' parameter.

Now, users can set content type explicitly for their files in a number of ways, or rely on automatic file-extension content types. Proxied files default to automatic file-extension content types, but then fall back to the content type of the resource they proxy to. There is also a bug fixed around correctly setting content type inside send_file. Fixes #821.
Merge remote-tracking branch 'origin/3.0-stable'
Update changelog with changes on master since 3.0.13
Include I18n::Fallbacks and set the default I18n locale to our default locale.

Thus, when a translation is missing in the current locale, fall back to the default locale. See https://github.com/svenfuchs/i18n/wiki/Fallbacks for more info and configuration settings available to users.

Also, this change adds a "t" helper that proxies to I18n.t, just like Rails, for more concise translating.
Merge pull request #853 from bhollis/i18n

Include I18n::Fallbacks and set the default I18n locale to our default locale.
Switch default markdown engine to Kramdown
Add i18n changes to CHANGELOG
Fix some 1.8.7 issues
Support fonts with asset_path
Upgrade fivemat
a first stab at partials_dir setting

re #252
feature for partials_dir setting