New config: Add config.rc files?

[The-Compiler]

#499 (comment) had quite some talk about a config.rc file which contains qutebrowser commands and is loaded on start.

Like mentioned there, I'd rather not do that at the moment, but I'd like to reconsider it at some later point (and that'd need to be after #2017).

[The-Compiler]

Looking back at this, I don't like the idea anymore. I think another yet another "config" file/format will just introduce more confusion.

For extensibility, this would likely result in qutebrowser inventing its own mini-language (see VimL 😄), while Python is much a better fit for that task (#30). Finally, with autocmds (#35) we should have an easy way to say "run this command on qutebrowser startup" already.