libpacman: Add FCompareDetector.
libpacman: Oups forgot declaration of _pacman_depmissinglist_add in previous commit.
libpacman: Add f_stringlist_remove_all.
libpacman: Use f_stringlist_remove_all.
Various comments/ident fixes.
libflib: Add private f_list_foreach_safe, not *safe* with current list implementation.
libpacman: Remove _pacman_pkg_dup, this was used in paths to have a clean copy in cache, but in the end the purpose is unecessary.
libpacman: Remove bogus test (replace is not a bidirectional link), add fix that trigger the issue.
libpacman: Remove now unsed _pacman_checkdeps.