Going forward for new installations, config and data files will be
stored at the platform default paths, as defined by
[env-paths](https://www.npmjs.com/package/env-paths).
For backwards compatibility, if the `~/.waveterm` or `WAVETERM_HOME`
directory exists and contains valid data, it will be used. If this check
fails, then `WAVETERM_DATA_HOME` and `WAVETERM_CONFIG_HOME` will be
used. If these are not defined, then `XDG_DATA_HOME` and
`XDG_CONFIG_HOME` will be used. Finally, if none of these are defined,
the [env-paths](https://www.npmjs.com/package/env-paths) defaults will
be used.
As with the existing app, dev instances will write to `waveterm-dev`
directories, while all others will write to `waveterm`.
This adds support for windows builds. With it, the app can successfully
run on windows and unix systems. Note that the terminal still only works
on unix systems at this time.
