[windows] Setting Windows PATH for Postgres tools

All you need to do is to change the PATH variable to include the bin directory of your PostgreSQL installation.

An explanation on how to change environment variables is here:

http://support.microsoft.com/kb/310519
http://www.computerhope.com/issues/ch000549.htm

To verify that the path is set correctly, you can use:

echo %PATH%

on the commandline.