Context: https://meta.discourse.org/t/introducing-discourse-splash-a-visual-preloader-displayed-while-site-assets-load/232003/17
We currently set the theme secondary color as the background for the splash, and this works and respects light/dark modes.
The issue is that we set it on the #d-splash div. That div doesn't have a specified height and only gets its height when the splash image loads.
This can cause a flicker effect where the <HTML> background shows for a fraction of a second while the splash image loads.
This PR sets the theme color on the <HTML> tag to alleviate this. This allows us to set the theme color a little bit sooner and should hopefully prevent the flicker effect from happening.
This PR also adds the theme-color <meta> tag for dark mode. Browsers that don't support multiple theme-color tags will ignore the second tag and fall back to the first one.
DEV: Replace instances of Discourse.base_uri with Discourse.base_path
This is clearer because the base_uri is actually just a path prefix. This continues the work started in 555f467.
Minor fixes to add Rails 6 support to Discourse, we now will boot
with RAILS_MASTER=1, all specs pass
Only one tiny deprecation left
Largest change was the way ActiveModel:Errors changed interface a
bit but there is a simple backwards compat way of working it
on iOS 10 behavior of zoom restriction has changed.
This does not disable zooming on iOS 10 but it DOES stop it from randomly
zooming when you are composing
The opensearch.xml results in a "site search engine" being added to
Chrome, while the sitelinks search tag results in "Search this website"
being added to Google Search.
