Initalize empty package sets with a proper empty file list.

Fix bug in razor_create_dir() path component loop.

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