Fbs

* Fix `FileNotFoundError` which sometimes occurred during `freeze`
* Move Windows-only setting to `windows.json`.

As in a previous version, this release jumps from 0.3.0 to 0.3.4 without going through 0.3.1 etc. because of a [problem with PyPI](https://github.com/pypa/warehouse/issues/4985).

Previously, had:

* src/
* main/
* resources/
* mac-frozen/
* linux-global/

Now:

* src/
* main/
* freeze/
* mac/
* installer/
* linux/

Another important improvement of this release is also that `startproject` now generates fewer files. Eg. `Info.plist` is no longer generated. When it does not exist in the "user's" src/ directory, fbs is now able to transparently use a default version.

Also removed `fbs.resources.generate_resources()` from the public API. If you really need to use it, it's still available as `fbs.freeze._generate_resources()`.

Finally, the `installer` command on Windows and Mac is now less verbose.

It allows you to declare dependencies. Eg. in `base.json`:

{
"hidden_imports": ["requests"]
}

It's now possible to create `.pkg.tar.xz` installers on Arch, and `.rpm` installers on Fedora!