Features:

* config: configs that do not need to be matched by fnmatch() could be using a
  vector instead of a list. This way we could search in it by calling
  bsearch().

* config: load on demand and provide a call to preload stuff

* kmod_module: create a mempool with live and recently de-allocated modules.
  This way we don't have to create a new one, parse dependencies and whatnot.
  Just pick the already created node.

* kmod_module: apply blacklist on module lookup. What's best? Return the whole
  list and provide functions like kmod_module_filter_* or return the list
  already filtered?
  ^-- investigate the best API

* insmod and rmmod with dependency handling. Maybe this should be done by the
  binary, and it's sufficient to return only the lists from lookups.
  ^-- investigate the best API

* when preloading stuff, give the possibility to preload binary files. We need
  to create alternative index_search* functions to operate on mmapped files.
  Then on ctx creation we mmap all the files