Consider moving all code into a top-level package

Electrum has now done this. As per the current setup.py, I assume we’d want our package to be called electroncash rather than electrum, otherwise it would be impossible to install both programs in the same environment. This will unfortunately make merges from Electrum harder than they were before, but no harder than they are right now since Electrum made this change.

Advantages:

• Using the same directory names in the source code and at runtime is simpler, and is the normal Python practice.
• The workarounds for the mismatching names can be removed from each of the GUIs, and will be unnecessary in the new Android app.
• It would make it easier to run the unit tests, as discussed in #723. Tests which are easier to run are more likely to be kept up to date. (The other test issue in that PR had been broken for over a month, so evidently nobody had run the tests in that time.)

Disadvantages:

• All open branches and pull requests will have to be rebased.
• The workarounds for the mismatching names must be removed from each of the GUIs.

[mhsmith]

Yeah, I don’t think that would be worth the trouble.

[kyuupichan]

I think this is a good idea. Electron Cash now warns it’s using obsolete features with Python3.7 because of the current hack