As of WordPress v4.5 which is schedulled for release on 12th April the core team has announced that universal site logo function will be included. This means all theme developers have to do is declare the support via
add_theme_support( 'custom-logo', size ) action and WordPress will do the rest.
So here’s how to go about adding the declaration and the required function that will generate the output of the logo for us.
If you have any questions or suggestions on improving the implementation please feel free to leave a comment and lets have a conversation.