first step - it is slower in the implementation for now, but all cases
seems to be sorted out.
Drop Flagged() and IsSet() from solver. the solver wont care, and only
the assertion value does matter (exception for uninstall)
Fixes races conditions and make the DB Switchable. Also prepare inside
the CompilationSpec the tree of the deps to be built, and parallelize
only the building jobs.
Closes#7
Signed-off-by: Ettore Di Giacinto <mudler@gentoo.org>
Uninstall can be done in different ways - the most accurate would be to try find a minimum subset of packages that gives conflicts and try to reduce them gradually.
E.g. this could be done with other SAT algorithms. For now we keep things simple and we compute the uninstalls as an indirect of an installation from an empty profile.
Also take care of corner cases where world has no clauses, and fixes a typo in building the world formula
