merge with stable

transaction: use the proper variable in '_addbackupentry' (issue4684) The 'file' variable was undefined but resolved to the 'file' built-in. This is why pylint complains about overwriting built-ins...

run-tests: python3.5 now supports mkdtemp using bytes for paths Now that http://bugs.python.org/issue24230 is fixed (thanks to Gregory Smith for that quick response!) we can drop one more ugly hack around path handling. Tests still pass in 3.5 with this cleaner version, as well as in 2.6.

run-tests: use items() instead of iteritems() This fixes the python3.5 build. We'll presumably want to build our own helper function or use 2to3 for this on the main source tree, but for run-tests we want a single-source version that works in 2.6 and 3.5.

selve: make 'shelve --interactive' not experimental It is safe to do as 'shelve -i' uses the same code path as 'commit -i' that is not experimental.

revert: fix edition of newly added file during --interactive Before this patch: editing hunks of newly added file when performing a revert --interactive had no effect: the edits were discarded. After this patch, the edits are taken into account.

revert: make revert --interactive use git style diff This allows us to use existing code to detect files that are newly added and modified. In turn, this allows us to make revert --interactive support editing newly added and modified files.

record: extract code to compute newly added and modified files We want to reuse this logic in revert.

record: extract ishunk to a function We extract this code as we want to reuse it in revert -i.

fileset: pretty print syntax tree in debug output