Also added a number of fixes for mobile enhancements, such
as serving a manifest.json file for Android devices, and
serving proper link tags for all uploaded touch icons.
This commit also creates a new template helper for link tags.
- Fixes issue where the served path for the favicon was incorrect (included relative path when one was not needed)
- Also fixes issue where favicons were just plain not served for subfolder installations
- Fixed unsemantic HTML in ACP/General regarding Site Logo and Favicon fieldsets
ability to select a default gravatar image (default, identicon,
mystery-man, monsterid, wavatar, retro) or upload a custom image to use
as default gravatar image
