Changes:
- Use git.io over 'https'
- Add extra check to conform to *.github.com URLs
- Use built-in _urls function for completion
- Update readme with GitHub blog URL
* Add some new git aliases, modify a few more.
* Add `gbV` command to show more verbose git branch info.
* Add `gcam` to make it possible to execute `gca; gcm '<your message
here>'` more simply.
* Add `gii` command to temporarily untrack (ignore) a file.
* Add `giI` command to uningore a file.
* Change alias of `gbl` to `gbv`. Personally, I think aliases that
include a switch in the command should include the switch in the alias
if possible. This makes them easier to remember.
* Change alias of `gbL` to `gba`. I think the `-a` switch is more
salient to what this alias does than the `-v`. Furthermore, with this
PR there are already `gbv` and `gbV` aliases, so those are out.
* Change implementation of `gCl` alias to use built-in capabilities of
git, rather than sed.
* Rename gbx and gbX to gbd and gbD respectively
* Mostly revert alias changes
* Add gbr and gbR aliases to gbm and gbM commands
