feat: implement list and generator function as valid locale parameters.

[steven-r]

The current setup does not allow changes in locales.
This PR enables passing of lists and functions to the locale parameter instead of a fixed language code.

The advantage is that dialects or local changes are able without forking or patching files.

As an example, I prefer writing vor einem Tag instead of vor 1 Tag (in the de-locale)

[steven-r]

... and as a remark: The __version__ field is not reflecting the current version (should be 1.0.16):

timeago/src/timeago/__init__.py

Line 15 in 3614536

__version__ = '1.0.14'