python - tin: Use dictionary pg_config.

Log Message:
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Use dictionary pg_config.

Stop using config.instance() and start using config.dictionary().

Alter cluster detection logic to also identify files that start with
'cluster_' in the cup directory. This was causing 'create' failures as the add
method might not see it if it's not see as a cluster directory(ie, if the
pg_conifg symlink was not created on initialization).

Modified Files:
--------------
tin:
setup.py (r1.3 -> r1.4)
(http://cvs.pgfoundry.org/cgi-bin/cvsweb.cgi/python/tin/setup.py.diff?r1=1.3&r2=1.4)
tin/src:
command.py (r1.6 -> r1.7)
(http://cvs.pgfoundry.org/cgi-bin/cvsweb.cgi/python/tin/src/command.py.diff?r1=1.6&r2=1.7)
control.py (r1.2 -> r1.3)
(http://cvs.pgfoundry.org/cgi-bin/cvsweb.cgi/python/tin/src/control.py.diff?r1=1.2&r2=1.3)

Removed Files:
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tin:
README
(http://cvs.pgfoundry.org/cgi-bin/cvsweb.cgi/python/tin/README)