Fixed #23827 -- TZ behavior in Storage API ref doc

This is derived from the current behaviour of FileSystemStorage.
Note that since this was not previously documented, other
implementations may not currently conform.
Use topological sort for migration operation dependency resolution

rather than an ad-hoc algorithm
Merge pull request #3525 from vanschelven/master

Use topological sort for migration operation dependency resolution
Merge pull request #3516 from jaylett/filestorage-timezones

Fixed #23827 -- TZ behavior in Storage API ref doc
Fixed #14030 -- Allowed annotations to accept all expressions
Revert "Use topological sort for migration operation dependency resolution"

This commit broke the tests on Python 3.

This reverts commit 13d613f80011852404198dfafd1f09c0c0ea42e6.