Follow XDG Base Directory Specification

Currently Brackets stores its configuration in toplevel of $HOME directory, which is bad practice under Linux. It should follow XDG Base Directory Specification.

[jasonsanjose]

Thanks for the heads up @fwmfftvh. Tagging medium priority.

[JeffryBooher]

Nominating for Sprint 31

[njx]

Assigning to @jasonsanjose since he has a pull request up for it already.

[ingorichter]

@ghost @jasonsanjose This commit adobe/brackets-shell@684eaf4 basically fixes this issue. We are using the g_get_user_config_dir function which makes use of the XDG environment setup.

[ingorichter]

Close, since it's already implemented.