psqlODBC website face-lift

The psqlODBC website, at psqlodbc.projects.pgfoundry.org, is a bit
outdated. It's missing links to the new git repository (it didn't have a
link to the old CVS repo either), the pgfoundry page, and the downloads.
Also, it doesn't look modern.

I created a little mock-up of what the site would look like using the
main PostgreSQL web site's style:

http://psqlodbc.mooo.com/

(that domain is just a temporary address for showcasing this - I'm not
proposing that we change hosting)

The sub-pages, like the howtos and faq, are unchanged. On the front
page, I created a new "history" section, and move there the paragraphs
talking about history from the introduction section. I created a section
for "psqlODBC development", with links to the mailing list archives and
the git repository. I also added a link to the downloads page in the
introduction - that's the first thing that users look for, so it's good
to have it at the top. The important links are also available in the top
navigation bar.

I think this page now contains all the important information about the
project. I propose that we replace the contents of the current web site
at psqlodbc.projects.pgfoundry.org with this.

I don't know what the PostgreSQL project's policy is on using the
website graphics and stylesheets, but we can work that out.

- Heikki