when looking for committees in bill action lines, "House|Senate" was duplicated in the regex
'On the Resolution of Ratification' vote types were being turned into type='On the Resolution' and category='passage' because regexes overlapped and needed to be reordered
add a --diff option for bills and votes to test if output has changed

When --diff is specified (for bills & votes), instead of writing output files to
disk, we run a diff over the existing file and the new content and display the
diff. This is handy for testing.

At the same time I'm removing my previous preserve_update_time flag which
I had been using for a similar purpose, but this new method is much easier.

reverts 5122ad6f966ba5899a0758ed92d81ca779314c7f
in vote XML output, map Guilty and Not Guilty to +/- option keys for compatibility with GovTrack data
bug in removing Yea/Nay options from Senate Guilty/Not Guilty votes, the wrong XML field was used

This was a bug since the beginning (a1da46b78fc5c52881016109e53d664d8e51afd6), unless the Senate's schema changed?
add a new vote category for House impeachment votes

This catches a handful of cases around h418-111.2009 and h102-111.2010, but not other cases like the Clinton impeachment which are not marked-up well by the House
handle the vote of a dead man