[gc] clean up and update api POD docs
[gc] clean up and update api POD docs

FROGGS/parrot,youprofit/parrot,tewk/parrot-select,gitster/parrot,youprofit/parrot,gagern/parrot,parrot/parrot,tewk/parrot-select,gitster/parrot,parrot/parrot,parrot/parrot,youprofit/parrot,tewk/parrot-select,youprofit/parrot,gagern/parrot,tkob/parrot,tewk/parrot-select,gitster/parrot,tkob/parrot,youprofit/parrot,gitster/parrot,FROGGS/parrot,tkob/parrot,gagern/parrot,tewk/parrot-select,tkob/parrot,gagern/parrot,tkob/parrot,youprofit/parrot,FROGGS/parrot,FROGGS/parrot,youprofit/parrot,FROGGS/parrot,gagern/parrot,tkob/parrot,tewk/parrot-select,gitster/parrot,FROGGS/parrot,youprofit/parrot,gitster/parrot,parrot/parrot,tewk/parrot-select,tkob/parrot,gitster/parrot,gagern/parrot,FROGGS/parrot,parrot/parrot,gagern/parrot,FROGGS/parrot,tkob/parrot