Updated General Installation Page

[Chris Bennett <..hidden..>]

I used my work on the OpenBSD Installation page to update and correct 
the general installation page. There had been some errors previously 
about which passwords to use where, that is now clear. I have also added 
a clear section about adding datasets and users and then logging in to 
application. I'll flesh that section out in a little more detail later, 
but now someone knows what buttons to click first.

I think I have made it clear that:

1. There is a superuser: postgres
2. There is an admin user: ledgersmb
3. There are a variety of created users associated with created datasets

Only the created users are used in the regular application.

http://www.ledgersmb.info/install_help.html

Chris Bennett