pgAdmin web site issues

Dear friends,

Just a quick note about the latest modifications on the web site:

1) On the download page, packages are now presented by distribution (Debian,
Slackware, etc...) with direct access from the menu. Some sites require this
feature to simplify dowloads.

2) Short description of pgAdmin on the homepage. This description is also
available in the Advocacy page.

Any comments are welcome. Do not update the translation yet. The impact of
changes is very minimal (30 strings). We need to validate the changes
first...

Next week, I would like to propose an updated design:
- unique navigation bar on the left (like Raphaël proposed),
- more simple layout without indent (this will ease reading and RTL).

Cheers,
Jean-Michel