Password field for GitHub user on settings page

[krichly]

The password for the GitHub user should be configurable on the settings page, as it is not useful to be able to change the GitHub user but not the password.

[BraunTom]

@krichly We do not need to be able to specify a github password, because we use ssh keys (take a look at Setup).
Username and email seems only relevant that is knows who executed git commands

[chrisma]

we use ssh keys

While this is usually a great idea for daily developer use, it might not be ideal in this scenarion, as it involves generating and fiddling with ssh configs (as described in the setup) in order to setup the system. Using name + pw might actually be simpler.