Updated logo

* New font
* Removed redundant font folder
* Moved jetpack-icons.css and converted to sass so it can reuse the
generate font styles
Removed jetpack-icons files and moved CSS into admin
Readded jetpack-icons.scss and functions

This way the icon shows up outside of Jetpack.
Fell back to using image for logo (svg/png)

For compatibility. IE was having issues. Will revisit.
Merge branch 'logo'

Conflicts:
	class.jetpack.php