Fix epoch in rpm and rpmdb importer: epoch is an integer tag.

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)