PostgreSQL: Use all config options in rake db:create and db:test:purge

Yes, but #86 PostgreSQL: Use adapter's #create_database db:test:purge deals with modifying rake db:test:purge to use the create_database method, and this one fixes rake db:create to pass all the database configuration settings instead of just the encoding. (I also have #38 PostgreSQL: use template1 database on rake:db_(create|drop) which fixes both of them in the case that there isn't a PostgreSQL database with the same name as the connecting user.)

I was under the impression that separate patches were preferred, although all three (in my opinion) are needed to get working rake tasks. If you would prefer a single patch file, I get submit one.

We do generally prefer seperate patches, but with the new git patch methods ( http://rails.lighthouseapp.com/p... ) it's a lot easier.

If you want to tie all the tidying into one postgresql fixes patch, I'd be happy to review and apply.

Thanks again!