These are the core interfaces in the new API:
rpool - Interface to interact with the repository pool.
rindex - Interface to interact with repository indexes.
pkgdb - Interface to interact with local packages.
transaction - Interface to interact with a transaction.
This also brings new repository index format, making the index file
per architecture and being incompatible with previous versions.
The transaction frequency flush option has been removed, and due to
the nature of package states it was causing more harm than good.
More changes coming soon, but the API shall remain stable from now on.
There's no need to prop_dictionary_copy the returned dictionary to
later have to free it again, just return directly the dictionary and
avoid the free(3)s.
1- We can cache the result of the first xbps_pkgdb_init() when it fails
and avoid the malloc/free/access from it.
2- We cache the uname(2) result into a private var in xbps_handle and
use it in xbps_pkg_arch_match().
This improves performance by ~5% approx and it's close as it was before
introducing the repository index format 1.5.
