transaction: mark backup-related attributes private As the transaction is gaining more functions and attributes, it is important to clarify what is part of the public API.

transaction: document the contents of `tr.backupentries` Now that all items are known we can document it.

transaction: drop the third item in `tr.backupentries` This third item is always None and never used.

rebase: fix rebase with no common ancestors (issue4446) The new rebase revset didn't check for the case when there are no common ancestors. Now it does. The new behavior should be the same as the pre-3.2 behavior. Added a test.

test-run-tests: accept more levels of precision and trailing ws (issue4440) simplejson produces slightly different output from the built-in json module, specifically: * It uses 0.000 instead of 0.0000 * It likes to put a trailing space after a comma This change works around both of those variations.

merge with stable

changegroup.cg2packer: lookup 'group' via inheritance chain This lets extensions insert themselves in the class hierarchy.

context.status: only filter suspect symlinks in the dirstate status We don't care about filtering out symlinks that have already been committed with full content, only those that have been accidentally resolved in the working directory.

context.status: inline _poststatus() By inlining _poststatus() into _buildstatus(), it becomes clearer that it is only called for the workingctx.

context.status: remove now-empty _prestatus()