Add config scopes

[jlorieau]

Add config namespace scopes, which are filled in by checks. These can then be cached and used by programs to access configuration values.

[jlorieau]

Add a dest flag for populating configuration with the parsed values. For example

checkUsername:
    desc: Get the current username
    dest: $ENV.user.username

[jlorieau]

Moved configuration to thatway