Basically reverts the last font related commits since pointSize isn't
as reliable as pixelSize.

Also some layout values (margins, spacings) have been moved out to Config.h.

* Validate both inferred and explicitly entered server addresses by attempting to call the /versions endpoint
* If the domain from the mxid fails validation, try prefixing it with 'matrix'
* Only show server address field if address validation ultimately fails

- Fixes small font issue on MacOs

Minor stylistic refactoring

closes #29

[ci skip]

- Minor refactoring

- Rooms without any history will be shown.
- Room's state will be kept in sync and any updates will be visible.