libpacman: Make pmtrans_t::add output last added pmsyncpkg_t by optional output parameter.
libpacman: Make pmtrans_t::packages beeing computed when starting pmtrans_t::prepare.
libpacman: Drop PM_TRANS_PACKAGES, add PM_SYNC_NAME.
libpacman: Remove some now uneeded usage of pmtrans_t::packages.
libpacman: Make pmtrans_t::package a FList<Package *>.
libpacman: Make _pacman_resolvedeps 4th parameter a FList<libpacman::Package *>.
libpacman: Remove dummy statement.
libpacman: Remove a bunch of unecessary casting when deferencing iterators.