fugitive.vim 2.5

* Support :source and :write on Fugitive URLs.
* Support :Gedit +cmd ++opt.
* Support :Gedit /absolute/path and ./relative/path.
* Support expansion flags, like :Gedit %:h.
* Support completion of commits for --fixup=/--squash=.
* Support :Gread commit to read commit message.
* Adjust :Gbrowse line range for upstream head.
* Map <CR> in blobs to jump to blamed commit.
* Map p to jump to file in preview window.
* Make :Gmove always relative to repository root.
* Load Projectionist config from .git/info/projections.json.
* Drop instaweb support.
* New public function API.
* Major robustness and error handling improvements.
* Bug fixes.