[Folks] Bugs

Fixed issues:
- MAGETWO-59053: [Github] Merge CSS Files causes entire site to load Extremely Slow #4321
- MAGETWO-59352: Variations and Constraints Review for automated functional tests in UI module

Issues fixed:

- MAGETWO-60283 Prices of configurable product are incorrectly recalculated when display currency is changed
- MAGETWO-53583 "Use Default" checkbox is checked again after saving empty fields (description, name, etc)
- MAGETWO-43911 [GITHUB] Untranslatable string
- MAGETWO-60127 [GITHUB] Number input fields have invalid 'maxlength' attribute #7125
- MAGETWO-60128 [GITHUB] Customer Addresses: Can't convert undefined to object #7115

MAGETWO-53583: "Use Default" checkbox is checked again after saving empty fields (description, name, etc)

- add isolation for test

- Merge remote-tracking branch 'mainline/develop' into pull-primary
- Conflicts:
- dev/tests/functional/tests/app/Magento/Catalog/Test/Repository/Product/CustomOptions.xml

[Epam] Extend functional test coverage 

MAGETWO-60634: Add Price Type into Tier Prices

# Conflicts:
#	dev/tests/functional/tests/app/Magento/Checkout/Test/TestStep/SelectCheckoutMethodStep.php

MAGETWO-60453 DeleteSavedCreditCardTest fails on bamboo
MAGETWO-60572 [GitHub] PayPal.js error on checkout downloadable product #7000

Merging with remote branch, conflicts:
lib/internal/Magento/Framework/Interception/PluginList/PluginList.php

- Fixed file name

[Mavericks] Extend functional test coverage

- Fixed phpDoc
- Fixed misspelling in a class name

MAGETWO-55729: [Customer] Optimize performance for bundled products with lots of product options

- Fixed Customer edit form tab
- Fixed Address renderer