split up classes

[smhg]

It would be nice to have different classes for the different parameters that each trigger each other and in the end the day/night change.

Roughly:

Settings

IP
triggered by settings
(don't know if this really needs to be a separate class, maybe it is just part of coordinates)

Coordinates
triggered by settings and IP

Timezone
triggered by coordinates

SunCycle
triggered by coordinates and timezone

Each in their own file, each unit tested.
Each with their own caching: persistent (to disk) or in memory.

[smhg]

Tests: see Package Control's tests