Support recursive forks

[andybergon]

Pretty sure forks of forks (so not forked from the main repo) are not considered.

e.g.

http://gitpop2.herokuapp.com/Bensge/NativeDisplayBrightness

Highlighted ones are not counted (one of the recursive forks is 2nd in stars count).

[gMan1990]

same question
techgaun/active-forks#31