Merge branch 'feature/fs-theme-mode-v7' into develop

* feature/fs-theme-mode-v7: (308 commits)
  [helper-method]
  [fix] [minor]
  [add-ons] [features] [enhancement] Adjusted the feature comparison and pricing tab for add-ons without an annual prices.
  [add-on] [modal] [enhancement] Enriched the modal for freemium add-ons.
  [add-ons] When an add-on has both free and paid plans, show the prices range from "Free - {minPrice}".
  [add-ons] [optimization] Use the new endpoint that returns the add-on's plans, pricing, and features, all in one request.
  [license] Updated license from GPLv2 to GPLv3. Closed #166
  [sdk-starter] [enhancement] Added special protection for renaming the SDK's folder name (will auto identify the new folder).
  [themes] [account] Don't show the Account for free WP.org themes without any paid plans.
  [premium-updater] [cache] [fix] Since the default API cache was set to 24 hours, together with the WP 12 hours updates cache, users with a valid license had to wait up to 36 hours to see an update. Therefore, enforce a 1-hour cache when checking for an update, which will reduce the wait time to up to 13 hours on the Account page. Also, if forcing an updates check, flush the cache to immediately see any updates.
  [api] [cache] [enrich] Enriched the API caching logic to optionally check a different expiration period than the one was originally set when the cached value was set.
  [cache-manager] [enrich] Enriched the cache manager logic to store the time the cache was created and also enriched the has_valid() method to optionally check if the cached value didn't expire based on an explicit expiration period.
  [css] [compile]
  [css] [minor]
  [tabs] [add-ons] Hide the add-ons page title when running within a tab context.
  [sections] [ui] [minor] Added a special styling class to the FS sections.
  [customizer] [upsell] [trial] [fix] Adjusted the upgrade link when running in a trial promotional period.
  [customizer] [upsell] Added "support" features based on the plan configuration.
  [customizer] [upsell] [feature-description] Added tooltips to the features that have a description.
  [tabs] [class] Added classes to FS added tabs for identification and consistency with the submenu items classes.
  ...

# Conflicts:
#	includes/class-freemius.php
#	includes/class-fs-api.php
#	includes/class-fs-plugin-updater.php
#	includes/fs-core-functions.php
#	includes/fs-essential-functions.php
#	includes/fs-plugin-info-dialog.php
#	includes/i18n.php
#	includes/managers/class-fs-admin-menu-manager.php
#	includes/sdk/FreemiusWordPress.php
#	require.php
#	start.php
#	templates/account.php
#	templates/add-ons.php
#	templates/auto-installation.php
#	templates/billing.php
#	templates/checkout-legacy.php
#	templates/checkout.php
#	templates/connect.php
#	templates/contact.php
#	templates/debug.php
#	templates/debug/scheduled-crons.php
#	templates/forms/deactivation/form.php
#	templates/forms/deactivation/retry-skip.php
#	templates/forms/license-activation.php
#	templates/forms/optout.php
#	templates/forms/resend-key.php
#	templates/forms/trial-start.php
#	templates/pricing.php

Author: vovafeldman