Merge pull request #1912 from sumobi/master

Use $item instead of $item['id'] in edd_email_receipt_download_title
Create edd_download_metabox_fields() function

This does a couple helpful things: 

1) Allows plugins to unset, for example, the download limit for Shop Managers.  Potentially useful if that field is irrelevant for a shop.

2) My primary use case, allows plugins to filter the is_protected_meta fields for each of the EDD fields.  Useful when exposing the Custom Fields metabox in EDD downloads and not wanting end users to be able to edit EDD meta.

This is utterly untested.
Whoops.
Merge pull request #1913 from JustinSainton/patch-8

Create edd_download_metabox_fields() function
Round EDD_Fess->total. #1918
Fix broken address email tag. Close #1911
Modernify edd_download_meta_box_save()

This PR does a few things:
* Cleans up coding standards (whitespace, braces, Yoda)
* Removes unused $edd_options global
* Adds second parameter to the save_post hook.  This allows for less reliance on global $post, which can be too easily stomped, and should be backwards compatible.
* Adds 'edd_save_download' action with $post_id and $post passed to it.  Obviously, plugins can also hook into save_post, but it seems more logical to have a unique action to hook into, so third parties don't have to do the same sanity checks that fill the first 15 lines of the function.
Merge pull request #1920 from JustinSainton/patch-8

Modernify edd_download_meta_box_save()
#1917 - Fixing Flat discounts applying to all items in the cart
#1917 - Applying strtolower for sanity check in case it comes back any other case
Removing strtolower's for a single strtolower in the edd_get_discount_type function
Merge pull request #1921 from cklosowski/master

#1917 - Fixing flat discounts applying to all items in cart
Fixing notice when no discounts are applied
Remove fees if cart is empty. #1925
Merge branch 'master' of github.com:easydigitaldownloads/Easy-Digital-Downloads
Merge pull request #1924 from cklosowski/master

Fixing notice when no flat discounts are applied
Actually remove fees if cart is empty
Take  *  in edd_get_Cart_content_details() instead of edd_get_cart_item_tax().#1926
Change Default Colour to Grey for Checkout Cart Submit Button
Change Default Colour to Grey for Checkout Cart Submit Button