5.0.0 Alpha 6

#1557: Grey out uneditable areas while the page editor loads
#1551: Miscellaneous fixes to third party development tools
#1558: Always process new state after exiting page editor
#1555: Configuring Widgets preserves Area details
#1556: Add a class_exists check to the trending controller
#1559: Fixed missing language string for "topicactivity_popularposts"
#1554: Page Editor UI Updates
#1552: Minor upgrader fixes
#1549: Fixed some alignment issues with the Menu Manager UI in the ACP
#1537: Block Manager UI pt. 2 - Better CTAs and Verbiage
#1521: Add profile completion to registration process
#1542: Improved the accessibility of "Wallpaper Carousels"
#1543: Fixed formatting and alignment of some ACP forms
#1544: Improved the UI of numerous ACP pages
#1545: Fixed z-index issue with "Repeat Event" dropdown
#1539: Increased width of block manager, and replaced search emoji with svg
#1538: Fix broken messenger Javascript
#1534: Fix exceptions on statistics pages
#1535: Clean up Database Filters widget
#1536: Removed the JS dependency for the sticky sidebar, and added a Theme Setting to toggle it
#1528: Block Sidebar part 1- Search, Custom Blocks and Favorites
#1491: Pages layouts improvements
#1506: Automatic Indentation and Wrapping Characters in Editor Codeblocks
#1523: Resizable Media Embeds
 - Issue #1433: Embed size and alignment 
 - Issue #1489: block span issue
#1529: Improved the "sticky offset" position of elements when a sticky header is implemented
#1493: More robust code highlighting loading process
#1504: Fix issues with widgets not displaying on database sidebars
#1505: Prevent v4 database templates from being imported
#1522: Navigation menu is no longer overlaid by Gallery image
#1515: Fix schema files to remove the popular_topics index (no longer needed)
#1516: Fix JS language string
#1517: Make only the last contextual search option selected
#1518: Fixed an issue where featured content did not always show an image
#1519: Fix issues where the presence of 3rd party apps breaks everything
#1524: Updated the UI of emails to match new branding
#1527: Fixed the broken Clubs grid in profiles
#1508: Fixed HTML validation, incorporated more semantic elements and added schema.org attributes
#1495: Custom CSS Updates