Client UI changes and Server improvements

UI:
Add buttons to enable speed and daily monitoring from the bandwidth tab
if not enabled.
Remove Settings child tabs for simplicity.
Changing the theme colour will save and restore on exit now.

Server:
Fix crash with loading and saving of daily usage when no SQLite DB/Table
found.
Redo parts of the ServiceManager to detect and correct a service running
from a different directory.
Condense some SelfInstaller code that was redundant.
Save the Daily Usage for some scenarios.

General:
Rename a lot of misleading and redundant classes, variables and folders.
(more to come)