Filtered continuous changes feeds report progress when filters fail

At times some filters are very strict and thousands of docs might
pass thru without success. If a timeout occurs the changes feed could
be requested again starting from the same sequence. This patch fixes this
by reporting a seq back to the controller even when the filter fails. The tricky
part is that this subverts the normal rexi mechanism of using inactivity
to determine a timeout has occured for purposes of a heartbeat. To solve this
an additional "time since last real change" is tracked in the controller.

BugzID: 17709
Account for failed filter messages by passing new timeout back to rexi
Send a no_pass message to fabric controller

When a filter function fails for a given document send the sequence back to
the controller. This enables long running changes feeds that may timeout
to return the last sequence processed to the caller. A count is maintained in
order to only send a message every so many times.

BugzID: 17709