Redo updates and removes in terms of a single razor_transaction abstraction

Redo updates and removes in terms of a single razor_transaction abstraction

Also does versioned depsolving at least partially.
Update main.c and test-driver.c for that, and fix some unrelated test-driver
bugs.

Now gets up to testUpdateSinglePackageObsoletesOldRequirement, although
it really should not be passing the multilib tests; apparently they aren't
clever enough in their testing of the depsolving algorithm and are allowing
it to come up with the right answer for the wrong reason.