Feature request: support "portable" mode

[jsumners]

A "portable" app is one that can be run without relying on an install or traditional system paths, e.g. no ~/Library/ files. See https://portableapps.com.

I would like to use this app in such a fashion. I use Moneydance for my personal finances, but am looking to use Wealthfolio for tracking my direct investments (an area Moneydance does not excel in). While Moneydance does not support a full portable mode, it works well enough in the following scenario to suit my needs:

I keep the Moneydance.app bundle, and its data file (all of my personal data), in an encrypted sparse image that I sync to cloud storage. I would like to do the same for Wealthfolio.

I haven't really setup this app yet, but it looks like the main thing that would need to be supported is being able to specify where the data file resides.