faster: use a hash table with pkg names on the transaction dict,
the process of collecting and sorting is now 50x faster or
even more (kde5).
bugs: this now detects cyclic deps and returns with an appropropiate
return value: ELOOP and ENOENT in xbps-query(1) --fulldeptree.
Ping me if you need more details :-)
Close https://github.com/void-linux/xbps/issues/16
Close https://github.com/void-linux/xbps/issues/5
These routines return a xbps_array_t with a full sorted dependency graph
for the target pkg, by querying pkgdb or rpool.
Update xbps-query(8) to use the new libxbps API.
