Fix significant problems with a previous upgrade script.

Add pg_extension_v and related functions.

# Improvements to trigger__parse() Add output fields for the table a trigger is on, as well as the function the trigger is using. Based on work done by Luís Lizardo (https://github.com/lizardoluis).

This changes the behavior of trigger__parse()! You can get the old behavior by passing the function_arguments output of trigger__parse() through trigger__args_as_text().


Add function__arg_types().

Add object type functions (object__catalog(), object__reg_type(), relation__kind(), relation_relkind()).

Add regprocedure().


Add support for Postgres 9.1 and 9.2

There are no SQL changes in this version.


=## BUGFIX: Fix trigger__get_oid()


=## BUGFIX: Drop pg_temp objects created by extension

It was not possible to actually install 0.1.2 and 0.1.1 because they left temporary objects behind. During session cleanup, the cascade drop of those objects would cascede to the extension itself.


=## BUGFIX: Install upgrade script


=## Add cat_tools__usage role

Previously, granting permissions to use these tools was difficult. Now all you need to do is grant cat_tools__usage to roles that you would like to have access to these tools. Keep in mind they are not meant for use by people, only by code.