End date with export library

[damajor]

It seems that --end-date is not used for podcasts when exporting library.

[mkb79]

Thank you for your pr. You're right, there is an issue with podcasts and stop date. This has to do with how the Audible API processes requests. It seams that child elements like episodes of a podcasts will be responded, even if the episode is out of the stop date. This can be handled be a function, which I have to implement.

[damajor]

More info just in case.

downloads:

• MP3 podcasts added after --start-date are always downloaded even if --end-date is earlier than the added date.
• AAX[C] podcasts added after --start-date are always tried to be downloaded even if --end-date is earlier than the added date, but all downloads fail.
• AAX[C] podcasts added after --start-date are downloaded fine when --end-date is later than the added date.

library:

• Library export always includes MP3/AXX[C] podcasts outside --end-date