Add several agents related to Nextcloud

[sclu1034]

• ab576d9 adds Evolution's user agent for "on the web" calendars and address books.
• 820bf4d adds Roundcube's CardDAV plugin. Prior to v0.9.0 (about three years ago) they used RCM CardDAV plugin/TRUNK between releases, not sure whether I should add that as well. After v0.9.0 they changed to a -dev suffix which I added to the regex.
• ff51462 adds the app DAVdroid. They use version suffixes depending on where you download the app (e.g. 1.9.2-gplay on Google Play, 1.9-ose on F-Droid), not sure if I should add these to the version output.
  I also had to put this quite high in the SPECIAL CASES TOP as they include OkHttp in their user agent which is matched as a "downloader..." (add okhttp #185).
• 631c5e4 adds the Nextcloud desktop sync application. The Owncloud version could probably be added to that regex as well, but I don't have anything to test it with.
• 5aa11ba adds the official Nextcloud android app. Sadly the app didn't change its user agent after forking from the Owncloud version, so they still send owncloud-android.

[commenthol]

Thanks for the work.