Added a destinations page, which lists all invoices from delivery windows in the same time frame
Re-grouped delivery windows by date and time.
Re-styled summaries page to accommodate this change.
Renamed url for destinations page
Removed debug statement; renamed file names in accordance with function names; changed dict comprehension to list comprehension
Included destinations.html; converted dict comprehension to list comprehension
Merge pull request #18 from this-username-is-taken/destinations

Destinations Page
Details page: groups same items sequentially together instead of combining them
Details page: Added sub check box for shopping list
Details page: fixed javascript var name
Details page: added a counter to avoid confusion in the case when deleting two items with the same name and quantity
Changed some variable names
Modified sorting function
Summary page: not show delivery windows with only pending orders
Summary page: Added day of the week
Merge pull request #26 from this-username-is-taken/details

Details page: group same items together in shopping list
Merge pull request #28 from this-username-is-taken/day_of_the_week

Summary page: Added day of the week
filter once
Merge pull request #27 from this-username-is-taken/pending_order_fix

Summary page: not show delivery windows with only pending orders
Fix: wrong usage of reduce function when sorting order_items.
Merge pull request #29 from gregwym/fix-detail

Fix: wrong usage of reduce function in sorting order_items.
Fix: shopping page image url.