uses gravatar_image_tag gem as standard avatar lib
fixes % sign on progress bar
styles work_package#show based on changes to avatar
uses default avatar on activities
removes duplicate avatar stylings and scopes them to wp split_view
consolidates avatar css
removes stylesheet import - included two times otherwise
corrects usage of avatar throughout the application
rewrites scss as sass to use variables
Merge pull request #1725 from opf/fix/use_default_avatar_lib

Fix/use default avatar lib