Factor out region-specific functions and variable

[xamanu]

There are some function calls and variable names in Portuguese language. I have spotted them primarily in the osm_routes.py file. These should be cleaned up.

[grote]

This is related to #9, maybe even a duplicate. I used non-english names for region-specific variables and methods. One idea is that region specific plugins/modules extend these classes and add their custom variables and methods to these sub-classes.

[xamanu]

Yes, indeed this is a duplicate because the proposed changed in #9 would move those into a special Fenix class, where this can still be living in and makes sense there.

[xamanu]

Tackled now in #40