API for triggering view updates
make sure we can pass a db name to couch_mrview:trigger_update/{2,3}
add /<db>/_design/<ddocname>/_reindex handler

When you 'POST' on the _reindex handle all the views of the group will
be reindexed.

close #RCOUCH-36
fix: make sure we only get results from last sequence when using a
composite key.
fix: log removed keys

When a key is removed make sure we correctly remove it from the records.
view changes: handle case where the doc is deleted

With this change we also emit a changes when the doc is removed from the
view.
add multi view queries support

This changes implement COUCHDB-523 with support of the multiview query
for the view changes and the replication using a view.

You can pass multiple queries to a view using the following format:

{"queries": [
   { "startkey": "a", "endkey": "c" },

   ....
]}