unduplicate file-finding code

add struct razor_transaction_resolver to reduce redundant procedure args

redo some of the transaction code, get conflicts and obsoletes partly working

now uses a bit array of to-be-installed/removed packages and uses that to
avoid needing to do either per-property searches or repeated merges. but it
really needs to have a bit array of properties too probably

checkpoint before starting on simplifying/cleaning up the existing
transaction code

add somewhat inefficient file dep removal code

(fwiw, the comment on the previous commit was incorrect)

implement file dependencies for installs

removes are trickier because there are no backlinks from the files array
the properties array, so there's currently no way to efficiently determine
what packages are affected by the removal of a particular file

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.

use -Wmissing-prototypes to help find dead code

(by forcing us to declare functions static, allowing gcc to tell us
"warning: foo defined by not used")

fix

redo razor_set_update to only rebuild the set once

messy, and with too much duplicated code...

fix one of the tests to match the probably mistaken python version, and
add two more comments pointing out oddities in the python tests