Fix bash git prompt (and set proper flags on ssh/config file)

The bash git prompt used to show branch name and file modification flags, like this:

`john@neptr: ~/.mydotfiles on fix-bash-git-prompt[+?!]`

But the flags went away when `git --status` stopped outputting as a comment (every line preceded by `#`). So this modification fixes that, and should be backward compatible with `git` versions that do output as comments.

I also went ahead and fixed the `ssh/config` file, whose permission flags need to be `rw-------` (600).