system-sync

- take list of installed packages (naevr) from one system
- produce a transaction or series of transactions to get the other system
  into the closest possible state
  

problems:
 - probably only consider latest versions of anything b/c it just gets silly
   otherwise
 - dealing with arch confusion if someone wants this system but in that arch
 

process:
 - break down the packages into n.a
 - compare to installed system
 - mark from remove anything installed that's not in the n.a
 - mark from install anything in the n.a that's not installed
 - print out errors for anything that is not available in a repo
 - depsolve the transaction
 - run it