finish and test site admin (Prestashop 1.6)

Finished Site Admin for all sites the saved token auth has access to
Tested it on ps1.6
Added http auth support

Added support for HTTP Basic Authorization, in case it's required to
access Piwik
Updated the proxy scripts to include the latest changes from piwik
default
Fix siteadmin for Prestashop 1.5

Closes #5, you can now set default currency in piwik from admin and set
the default currency to convert into before sending piwik requests
Added Report date to load by default Closes #1

Report date to load by default from "Stats => Piwik Analytics"
Today
Yesterday
Previous 7 days (not including today)
Previous 30 days (not including today)
Last 7 days (including today)
Last 30 days (including today)
Current Week
Current Month
Current Year
add new vaules to upgrade file
Merge pull request #10 from mdurys/master

Added Polish translation