Remove n+1 line item lookup. Fixes #5481
Fix Order#merge! for custom comparison hooks.

Custom comparison hooks expect a Hash as `options` parameter,
but a LineItem object was passed instead.

fixes #5589
Fix Asset position for different viewables.
fixes #5590
remove permitted_resource_params as it is already present in resource controller

fixes #5591
Add is_backorderable to variant and small RABL view
fixes #5595
Update MoveOrderTokenFromTokenizedPermission migration to work w/ jruby

jruby mysql adapter uses adapter_name 'MySQL'. Not recognizing this causes migrations to bomb out on jruby due to invalid SQL syntax.

https://github.com/jruby/activerecord-jdbc-adapter/blob/master/lib/arjdbc/mysql/adapter.rb#L109

fixes #5597
Fix spec broken by 54a5e4851b2b54750cf4a17d88a6566b1b255dac
Only charge for unreturned exchanges when the new item is in the shipped state.

* In the case when the customer returns the new item, we don't want to
charge them for changing their mind.
* In the case when the shipment was caught on its way out and is still
'on hand', but the customer has not received inventory, we don't want
to charge them for our internal mistakenly placed shipment.

fixes #5598
Mentioning admin order flow changes.

fixes #5599
Validate authenticity token on all actions but populate

fixes #5601
Add 2.0.0 to travis to see difference from 1.9.3
Update contributing seciton of readme.
guides no longer in their own repo.
Link to license from readme.
Add rack-mini-profiler to sandbox.
Add total on hand to variant RABL

added test coverage for new rabl fields

fixes #5593
Skipping the set_current_order before filter on the cart link action as this should use the simple_current_order helper only

fixes #5605
Don't load the store if we don't have to - minor optimisation but every bit helps
fixes #5606
Test agaisnt latest ruby
Move default price to a concern.

fixes #5505