###### Motivation for this change
Update to latest upstream version
###### Things done
* [ ] Tested using sandboxing ([nix.useSandbox](http://nixos.org/nixos/manual/options.html#opt-nix.useSandbox) on NixOS, or option `sandbox` in [`nix.conf`](http://nixos.org/nix/manual/#sec-conf-file) on non-NixOS linux)
* Built on platform(s)
* [x] NixOS
* [ ] macOS
* [ ] other Linux distributions
* [ ] Tested via one or more NixOS test(s) if existing and applicable for the change (look inside [nixos/tests](https://github.com/NixOS/nixpkgs/blob/master/nixos/tests))
* [ ] Tested compilation of all pkgs that depend on this change using `nix-shell -p nix-review --run "nix-review wip"`
* [x] Tested execution of all binary files (usually in `./result/bin/`)
* [ ] Determined the impact on package closure size (by running `nix path-info -S` before and after)
* [ ] Ensured that relevant documentation is up to date
* [x] Fits [CONTRIBUTING.md](https://github.com/NixOS/nixpkgs/blob/master/.github/CONTRIBUTING.md).
###### Notify maintainers
cc @blitz @Ma27 @tfc @worldofpeace
The stgit package is installing using make, which leaves the application in a state where it can not properly find the installed package stgit.
---
File "/run/current-system/sw/bin/stg", line 35, in <module>
from stgit.main import main
ImportError: No module named stgit.main
---
This is fixed by using buildPythonApplication instead of stdenv.mkDerivation.
In that case it specified $doc output but didn't even create it.
I expect it's better to do it this way instead of creating it
as an empty directory.
(Only the failed builds get rebuilt by this commit.)
disable_test: Use \s instead of ' ' as tabs are used for indentation in
t5324-split-commit-graph.sh. It's also necessary to insert : (no op) in
front of # to prevent Bash syntax errors due to empty loops.
Two newly added tests fail due the usage of shared permissions (outside
of the build sandbox they succeed, actually even with breakpointHook
(cntr attach + cntr exec bash)):
```
t5324-split-commit-graph.sh (Wstat: 256 Tests: 29
Failed: 2)
Failed tests: 28-29
Non-zero exit status: 1
```
I'm also adding myself as maintainer since there currently doesn't seem
to be a fixed one for regular updates.
Announcement:
https://lkml.kernel.org/lkml/xmqqzh9mu4my.fsf@gitster.c.googlers.com/
