add profile-command utility
do not get last_uid from the set of soledad messages

but always from the counter instead. once assigned, the uid must
never be reused, unless the uidvalidity mailbox value changes.
doing otherwise will cause messages not to be shown until next session.

Also, renamed get_mbox method for clarity.
fix repeated recent flag
call notify in reactor
make the condition optional
catch typeerror too in empty definition
separate new and dirty queues
fine grained locks for puts
fix last_uid write to avoid updates to lesser values
fix several bugs in copy/store
improve flag-docs relative internal storage