Simplify logout and remove bad <a>
FeaturedProduct CMS field changed to correct name
Add 'Featured' as a searchable field

All my clients ask for this :)
Merge pull request #234 from nimeso/patch-12

Simplify logout and remove bad <a>
Merge pull request #236 from nimeso/patch-14

FeaturedProduct CMS field changed to correct name
Merge pull request #237 from nimeso/patch-15

Add 'Featured' as a searchable field
Removed shipping specific code from shop core
Tidied up CartPage and CheckoutPage find_link functions.
Code tidy OrderTest.php
Removed ProductVersion variable from cart fixture. This shouldn't be present, because the version is only set once order is placed.
Removed 'canCreate' function from CartPage. There can sometimes be a rouge cart page in existence, which causes problems for admins who want to create / edit a cart page. Not sure what the best solution to fix is, but this will do for now.
Make sure order receipt is only sent once order updating has finished (so that sent data is correct).
Fixes: #238
Minor code tidy
Moved some checkout/member configurations to yaml.
Created ShopMemberFactory.
Removed some unused code.
Tided & commented code.
Test and (temp) fix for components failing issue

resolves #217
Removed ProductVersion fields from cart fixtures, as it shouldn't be there.
Added discount submodule suggestion to composer.json.
Removed old composer silverstripe-payment config.
Added default product image
ProductImageTest now uses shop.yml fixture
Merge pull request #242 from markguinn/feature-default-image

Added default product image