#141637 follow up patch by merlinofchaos: proper placement of menu_rebuild() to not run twice on the same request

#136837 by meba: PHP replaces {} enclosed variables in strings with the variable value itself, so cache tables were not prefixable

#141637: add back menu_rebuild() to allow for clean URL check, and document the need for both menu_rebuild() calls, so we will not make this mistake in the future

- Modified patch #142798 by Steven and sime: introduced a new image API function: image_scale_and_crop()

#141637 by merlinofchaos and yched: follow up fixes to the installer patch, properly rebuilding the menu when done and returning update results

- Patch #142897 by erdemkose: corrected the argument: should be empty array instead of empty string.

- Patch #141637 by merlinofchaos, gabor, et al: provide a site config form at the end of install to collect data, plus allow profiles to modify and add more.

- Patch #99011 by merlinofchaos: remove sites/default/settings.php and ship with sites/default/default.settings.php.

- Patch #137211 by merlinofchaos: move theme information to .info files and improved theme inheritance.

#141482 by Heine: collapse custom language addition form by default, because it is an advanced form, not required most of the time, so can make people confused

#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.

by Moshe Weitzman, webernet, chx, erdemkose and myself

Add missing items to changelog (clean url tester, sticky table header) and group related items together.