Add settings screenshot for README.md.
Merge branch 'frodo'
dos2unix strings.xml as it is failing an xbmc check:

addonpr.addonparser - ERROR   - Invalid end-of-line (CRLF) in
plugin.video.ted.talks/resources/language/Finnish/strings.xml
Add optional tags from http://wiki.xbmc.org/index.php?title=Addon.xml#Optional_information