- Patch #201122 by c960657, Moshe Weitzman: never write anonymous sessions, unless something has been written to . This is an important performance improvements -- as long as you use modules that use  carefully. It might be good to report some analytics about this in the performance settings page so administrators can see if there is a 'broken' module.

- Patch #243773 by chx, catch, boombatower, yched, dmitrig01, et al: use the batch API for running the tests instead of an all-in-one approach.  Great work.

- Patch #245115 by kkaefer, John Morahan, JohnAlbin et al: after a long discussion we've decided to make the concatenation operator consistent with the other operators.

#196630 by yched: postpone warning message display until batch finished, so messages are not forgotten on non-JS batches

 - whitespaces at end of lines
 - indentation
 - control structure usage
 - whitespace in empty lines
 - phpdoc comment formatting

#169079 by yched: improve consistency of menu API and batch API by allowing batch definition in non .module files, which opens the possibility of better performing batches (which are likely to reside in .admin.inc files generally)
 - apply this change in locale.module
 - improve batch API code documentation

- Patch #149576 by hunmonk: a bad query is preventing batch processing from working correctly. token is a string, so it should not be escaped as a number.

#127539: progressive operation support, refactoring update.php code to a generic batch API to support runnning operations in multiple HTTP requests
  - update.php is already on the batch API
  - node access rebuilding is in the works
  - automatic locale importing is in the works

 Thanks to Yves Chedemois (yched) for the good code quality, very wide awareness of issues related to batches,
 and the fantastic turnaround times. Hats off.