add missing friend 'class' Foo to fix compile error
add missing friend 'class' Foo to fix compile error

besser82/shogun,Saurabh7/shogun,shogun-toolbox/shogun,sorig/shogun,shogun-toolbox/shogun,karlnapf/shogun,Saurabh7/shogun,sorig/shogun,geektoni/shogun,Saurabh7/shogun,besser82/shogun,Saurabh7/shogun,lisitsyn/shogun,karlnapf/shogun,lambday/shogun,geektoni/shogun,sorig/shogun,besser82/shogun,lambday/shogun,lisitsyn/shogun,lisitsyn/shogun,sorig/shogun,sorig/shogun,besser82/shogun,shogun-toolbox/shogun,Saurabh7/shogun,lisitsyn/shogun,shogun-toolbox/shogun,karlnapf/shogun,lisitsyn/shogun,lisitsyn/shogun,Saurabh7/shogun,besser82/shogun,lambday/shogun,shogun-toolbox/shogun,karlnapf/shogun,sorig/shogun,Saurabh7/shogun,karlnapf/shogun,shogun-toolbox/shogun,geektoni/shogun,besser82/shogun,lambday/shogun,Saurabh7/shogun,geektoni/shogun,lambday/shogun,Saurabh7/shogun,lambday/shogun,geektoni/shogun,karlnapf/shogun,geektoni/shogun