Setting loader

The setting loader is a module that allows to load settings in the form of a JSON. This JSON file can include various parameters. We call them settings.

The settings should be overridable in the following levels :

• default settings in a setting folder, in a JSON file. We might use HJSON
• override settings loaded depending on the ENV : production / staging / development  This overriding should take the following form : load(settings/settings.${ENV}.json) if load(settings/settings.${ENV}.json) fail, tries load(settings/${ENV}.json) else tries load(settings/settings.json)
• override based on the default path where a setting can be found (inspired from rc):

• $HOME/.${appname}/rc

• $HOME/.${appname}/settings.json

• $HOME/.setting/${appname}

• $HOME/.setting/${appname}/settings.json

• Folder defined here: https://electron.atom.io/docs/all/#appgetpathname  

• override base on a file input : providing a --settings option then this setting file should be loaded. If the setting file can not be found or parsing is wrong, a warning should be thrown and the other setting should be loaded