deb cleanup

* use installed pg_buildext
* use installed pgxs_debian_control.mk
* 'make deb' forces control file regeneration

This reduces crap maintained locally.

It also does mean that to build against server-dev-X.Y package
that is not for Debians default Postgres version, following packages
need to be installed from PGDG (wiki.postgresql.org/wiki/Apt) repo:

  postgresql-client-common
  postgresql-common
  postgresql-server-dev-all
debian: simplify more

* don't track sql files one-by-one
* remove genpg.sh
* remove local pg_buildext
Merge remote-tracking branch 'gamato/master'
Refactor Consumer code.

    Common code from pgq.Consumer goes into new pgq.BaseConsumer, pgq.Consumer and pgq.LocalConsumer are now subclasses of pgq.BaseConsumer and pgq.Consumer adds retry api/logic.
    pgq.Event code is now split between pgq.Event and pgq.RetriableEvent.
    These changes reflect the fact that pgq.LocalConsumer should not be allowed to use retry logic.
Merge branch 'master' of skype-git:/git/dba/skytools-3
CascadedConsumer is now also subclass of BaseConsumer (does not allow retry)
Fix basescript docstring
Store naturaldocs customizations in tree.

Now unpatched naturaldocs should work fine.
Move more of retry logic away from BaseConsumer/Event classes
Merge remote-tracking branch 'petr/consumer_refactor'
pgq.event: __slots__ cleanup
copy-condition removed from londiste3 man page

This option is no longer available as londiste3 add-table option.
Removed in ccfcf87df7fe0a123b563efec1639dec8367c2da
BaseScript: skylog_locations config options

This allows to specify per-script skylog.ini
Merge pull request #20 from kitsemets/master

londiste3 add-table option --copy-condition removed from man page
londiste.handler: disable shortcut for specifying handler args together with its name

This will be allowed no more:  --handler="hname(arg1=123, …)"
It was a weak point through which Londiste setup could be broken.
Merge branch 'master' of https://github.com/markokr/skytools