Update german translation

[sgelb]

I updated the german translation, fixed some typos and rephrased some sentences.

[einmalfel]

@paskalito any comments on this? Will merge with your approval

[paskalito]

@sgelb thank you very much for the many good improvements!, after +- close review only two comments were left ^^

https://github.com/einmalfel/PodListen/pull/44/files#diff-cdca861e65ab0caf0dac48368b3fa2a6R93
might be too long
(maybe just test out)

https://github.com/einmalfel/PodListen/pull/44/files#diff-cdca861e65ab0caf0dac48368b3fa2a6R183
This sentence is in the more distant/undirect/polite "Sie Form" - whereas at least i decided to use the more close/direct "du form". (evendough i made a fault that @sgelb corectet out) so i propose to change it to the "Du form"

@einmalfel thanks for involving me :) i'm also excited about the experimental preferences :)

[sgelb]

@paskalito Thank you for the initial translation!

Regarding your comments:

1. The line has 41 characters, I think that's ok. Is there some advice how long those strings should be?
2. You misread that. sie refers to "Download-Manager"-System-App, not the user.

[einmalfel]

1. Not sure what line you are talking about (BTW on GitHub you can leave a comment for exact diff line). "preferences_*_title" strings should be as short as possible, ideally less then 30 characters. I wrote a couple of comments about restrictions like that in English strings.xml

[paskalito]

@einmalfel it is that one https://github.com/einmalfel/PodListen/pull/44/files#diff-cdca861e65ab0caf0dac48368b3fa2a6R93

@sgelb thank you :)

1. ok then it really might be to long.
   maybe leave it as it is.
   all the words are shorter there. - or another idea?
2. you're right, so even the last thing i found wasn't one ^^ - excellent work

[einmalfel]

@sgelb @paskalito
If there is no objections I'll merge all changes except for "preferences_max_downloads_title". Agreed?

[sgelb]

Thanks, go on. You could fix a small typo in the original "preferences_max_downloads_title", "Paralleller" has to be lowercase. Correct string is "Maximum paralleler Downloads".

[paskalito]

yes, all superb for me. :)