Support the XDG Base Directory Specification

[marwanhawari]

Currently stew stores all binaries and data in a $HOME/.stew directory but I would like to support the XDG Base Directory Specification instead.

This would mean moving ~/.stew to $XDG_DATA_HOME/stew (or $HOME/.local/share/stew if $XDG_DATA_HOME is not set).

[ComedyTomedy]

I'd love to have the option of putting binaries into ~/.local/bin/; it would mean that (at least on systemd systems) there's no need to add anything to the $PATH.

(Aside - Just found you through Reddit, or rather, by googling for a github binary package manager, and this is exactly what I wanted, thank you ♥)

[marwanhawari]

Awesome, glad to hear it! My first priority is coming up with how I want to allow for user configuration, because right now custom configuration is not really possible. Once I settle on how stew will read and write user config, then I don't think it will be too difficult to allow users to change the location of the stew directory or change the binary install path.

[marwanhawari]

Resolved in #8