anchor.diff:  * Only update response headers if we have a new one {pull}37590[#37590] (issues: {issue}35754[#35754], {issue}37530[#37530])
   
   Infra/Packaging::
  +* Upgrade bundled JDK and Docker images to JDK 12 {pull}40229[#40229]
   * Change file descriptor limit to 65535 {pull}37537[#37537] (issue: {issue}35839[#35839])
   * Exit batch files explictly using ERRORLEVEL {pull}29583[#29583] (issue: {issue}29582[#29582])
   
  
positive.code: * Fix handling of fractional time value settings {pull}37171[#37171]
  
  Machine Learning::
  * [ML] Fix datafeed skipping first bucket after lookback when aggs are … {pull}39859[#39859] (issue: {issue}39842[#39842])
  * [ML] refactoring lazy query and agg parsing {pull}39776[#39776] (issue: {issue}39528[#39528])
  * [ML] Stop the ML memory tracker before closing node {pull}39111[#39111] (issue: {issue}37117[#37117])
  
negative.code: * Fix NPE in CachingUsernamePasswordRealm {pull}36953[#36953] (issue: {issue}36951[#36951])
  
  CCR::
  * Safe publication of AutoFollowCoordinator {pull}40153[#40153] (issue: {issue}38560[#38560])
  * Enable reading auto-follow patterns from x-content {pull}40130[#40130] (issue: {issue}40128[#40128])
  * Stop auto-followers on shutdown {pull}40124[#40124]
  * Protect against the leader index being removed {pull}39351[#39351] (issue: {issue}39308[#39308])
  * Fix shard follow task startup error handling {pull}39053[#39053] (issue: {issue}38779[#38779])
  * Filter out upgraded version index settings when starting index following {pull}38838[#38838] (issue: {issue}38835[#38835])
  