add a force flag to disregard peer configuration differences

[GoogleCodeExporter]

If you are forced to change the filter_bits setting due to bloom filter
false positives, then we need to modify gross so that you can pass in an
option to ignore configuration differences.

It requires modifications to the syncing protocol.  There should be a force
flag to disregard the configuration difference.  Then you would be able to
do this:

1) Prevent client queries to server A (change port or disable proto)
2) Resize filters and restart the server A
3) wait until the servers are in sync again (number_buffers times
rotate_interval)
4) Make server A available to clients
5) do steps 1 to 4 with server B

Original issue reported on code.google.com by jesserth...@gmail.com on 9 Nov 2007 at 5:40