Update all adjustment types

In f9ed99a the order updater was changed to update only shipping
adjustments and promotion adjustments. This was done so that the
in-memory order was used for promotions calculations.

This broke some extensions which expected their custom adjustment types
to receive updates.

This goes back to the previous behaviour of updating all adjustments,
but uses the in memory order object if it is the adjustment's source.

Fixes #3960
Replaced Taxon :position refs with :child_index=

Fixes #3390
Fixes #3956

Taxon position unnecessarily fights against the awesome_nested_set
API. By using a_n_s's :move_to_child_with_index method we can more
fully leverage acts_as_nested_set.
Not attempting to reorder taxon on create since awesome_nested_set refuses
Bump to activemerchant 1.42.2

Conflicts:
	core/spree_core.gemspec
Bump aws-sdk to 1.27.0 to remove restriction for Nokogiri < 1.6
Bump to Deface 1.0.0
Update changelogs
Bump Rails version in README
Bump to 2.0.7
Bump to 2.0.8.beta
Blank out changelogs
Query only valid payments for order confirmation_required?

Prevent a confirmation step in cases where a previous selected payment
method which required confirmation failed and customer picked one that
doesnt require confirmation next

Fixes #3970
Set postgres host when creating a test_app

Fixes #3988
Remote erb inline comment from backend/payment_method/form

Motivation is to avoid parse errors when trying to deface that file

See #3913
Allow inventory tracking control (enable/disable) at the variant level. This retains the site-wide inventory tracking flag, but also allows this type of control down at the variant level.

Fixes #3974
Use different id on hidden field so associated labels work as expected

Fixes #3981
[backend] verifying if product picker returns any product

Fixes #4008
Inventory Tracking by Variant: fix resource controller model load issue
Merge remote-tracking branch 'godaddy/inventory_tracking_fix_pr' into 2-0-stable