libpacman: Preparations for makeking FList sortable.
libpacman: Define libpacman::package_set and group_set to avoid long declarations in future changes.
libpacman: Add iterable_traits<const Iterable *>.
libpacman: Drop util/falgorithms.h.
libpacman: Use libpacman::package_set and group_set on getters.
libpacman: Add flib::mapped_traits (to implement key/value in a single structure).
libpacman: Remove unused f_stringlistitem_to_str.
pacman-g2: Move list.c to list.cpp (to ease coding).
libpacman: Rename cache.cpp to database_cache.cpp.
libpacman: Make package and groups accessors, member functions of Database.
libpacman: Make _pacman_db_load_pkgcache static.
libpacman: Make _pacman_db_free_pkgcache an method of Database.
libpacman: Make _pacman_db_add_pkgincache a method of Database.
libpacman: Make _pacman_db_remove_pkgfromcache a method of Database.
libpacman: Make _pacman_db_get_grpfromcache a method of Database (as find_group).
libpacman: Drop cache.h.