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

Merge branch 'master' of git+ssh://people.freedesktop.org/~danw/razor

Conflicts:

razor.c

make razor_set_update not loop forever on unsatisfiable dependencies

this is mostly a dead-end, as to get the next test working i need to
rewrite the code as suggested in the comment above razor_set_revalidate

redo razor_set_remove() to only do a single merge