keep track of both the install and the remove on an update

razor_transaction_satisfy_removes() is now quite broken, as it thinks
it should remove a package if a package it depends on was updated.

move razor_set_diff so it's not in the middle of the transaction code

clean up packages states some

checkpoint, misc rewritage

Fix version handling (particularly wrt epoch) on import

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