Remove attr_accessible in 'Custom Attributes' guide

Fixes #198
Update products + variants API examples for Spree 2.1
Attributes in Variant API examples should be shown before associations

Conflicts:
	lib/resources.rb
Remove count_on_hand from variants results
Update adjustments guide for Spree 2.2.
Fixed rendering of '```bash' in README.

Fixes #205
Fixed grammar error within Contributing to the Documentation section

Fixes #206
include option types in products resources
Deleted double can.

Fixes #208
Clarify that auto_capture? false still does authorization.
Remove unneccesary opinion
Drop integration guides

Replaced by http://spreecommerce.com/hub/
Add google webmaster tools verification
Use can_supply in stead of deprecated in_stock in frontend

Fixes #4364
Remove unused font-face styles
Remove the spreeconf widget
Fix broken links in footer navigation
Bump factory_girl_rails to 4.4.0
Correct Rails version in readme
Bump Spree master to 2.2.1

Master should be higher then the latest stable branch.