Fixes #1659
Fixes #1642

Closes #1502

I temporarily removed this during the refactor so it needed to be added
back. This time I bundled it with the nbin loader code since it's all
related (will also make it easier to remove).

Fixes issues with unexpected characters breaking things when setting the
cookie (like semicolons).

This change as-is does not affect the security of code-server
itself (we've just replaced the static password with a static hash) but
if we were to add a salt in the future it would let us invalidate keys
by rehashing with a new salt which could be handy.

Fixes #1062.

Fixes #929.

This means that you have to turn on features now instead of disabling
them like auth and https.

In addition:
- Allow multiple options for auth (only password for now).
- Combine the install docs since they had many commonalities and
- generally simplified them (hopefully not too much).
- Move all example configs into docs/examples.