Log Message:
pkgconf: update to 2.4.3.

Changes from 2.4.2 to 2.4.3:
----------------------------

* Fix additional logic errors relating to the new fragment trees
  functionality.

Changes from 2.4.1 to 2.4.2:
----------------------------

* Fix several logic errors in the pkg-config file parser that were
  surfaced by recent refactoring work.

* Fix BSD make compatibility so that it generates the test data
  before running kyua on BSD make implementations.

Changes from 2.4.0 to 2.4.1:
----------------------------

* Ensure the full DAG is solved for all query types.