Fix Ukrainian translation

Fixes issue 6101
Update Brazilian Portuguese translation
Update French translation
Merge branch 'translations'
Add posteo.de to providers.xml

Add Posteo.de to providers.xml (according to https://autoconfig.thunderbird.net/v1.1/posteo.de and https://autoconfig.posteo.de/mail/config-v1.1.xml)
Add Azet.sk to providers.xml
Merge branch 'providers'
Add work-around for Asus Transformer WebView display bug
Make IMAP autoconfig recognize "Draft" as drafts folder

Yahoo names it "Draft" instead of the more common "Drafts".
Set minSdkVersion to 15

Technically, the code still supports SDK 8. But we don't want users to get stuck
on a 4.9xx version when we do remove compatibility with old Android versions.
Revert "Make IMAP autoconfig recognize "Draft" as drafts folder"

This reverts commit 453f10128c0500e7165f22e806fc1ce4e3623dd5.
See https://github.com/k9mail/k-9/pull/429
Fix ClassCastException