Selectable Logos 1.4.1

• Push $svSelectedLogo variable into page params so it is usable in PAGE_CONTAINER template
• Document $svSelectedLogo template variable's existence;
  
  The current selected logo is exposed to the template system as $svSelectedLogo
  • $svSelectedLogo.isScheduled() Indicates if the logo is apply because it is scheduled
  • $svSelectedLogo.isCustom() Indicates if the logo is apply because it it was user selected

• Require StandardLib v1.24.0+
• Add an "Selectable logo type" style property to define per-style how the selectable logos are selected (ie default or alt image), and allow the alt image to be filled even on XF2.2
  This allows a selectable logo to work with multiple styles which are light or dark

• For XF2.3, if Svg Template is installed, recommend updating to v.2.6.3
• Allow {styleType} (aka light/dark) to be pushed into the url/template name to be used for the selectable logos

• Inject classname into <html> element if the logo is user-selected (html.selected-logo--custom) or scheduled (html.selected-logo--scheduled)

• Require StandardLib v1.22.0+
• Fix 2x image would be set as a duplicate of the overridden image url
• Fix XenBase styles would duplicate the mobile logo depending on configuration
• Fix optional selectable logo attributes could override style image urls to empty values
• Improve XF Cloud compatibility (removing use of assert() function)
• Add per-logo style variation support. Allows light & dark logos to override the main logo(s) on XF2.3+