Parent autoload

[da-h]

Parent Auto-Loading

This PR adds automatic loading of parent modules.

Example

I.e. consider the defined modules:

• parent
• parent2
• parent.level1
• parent.level1_second
• parent.level1.level2
• parent.level1.level2_second

Loading level2 will now load all modules that are direct parent modules of level2.
In this example mf will load (in the exact order):

• parent
• parent.level1
• parent.level1.level2

Things done in this MR

• implemented parent auto-loading as described above
• changes printing of loaded modules for the user. previously all parent modules would be listed one after another, together with the specific module (here level1). now, it will only list parent.level1.level2, but highlight parent and level1 to show that these are modules themselves.
• to allow special cases where this behavior is not desired, any module in the loading-chain can specify the variable register_parent = False (globally, as the register(mf) function) to disable automatic loading for this module
• adds tests for these kind of automatic imports

[sbrodehl]

Here is my feedback:

• I think the register_parents = False expression seems a little hacky, and without proper documentation might be overlooked. Is there a way to write somethings like mf.register_parents(False)?
• IMHO the link usage for the miniflask package is bad.