Calendar ICS adapter

Use a filemanager (i.e. https://f-droid.org/packages/org.openintents.filemanager), emailclient (i.e.
https://f-droid.org/packages/com.fsck.k9) or bluetooth to import or export android calendar entries via
*.ics or *.ical files or attachments of type text/calendar.

The android.calendar.ics.adapter has no gui of its own. If you open an event
from the android calendar you can choose between "view event" and "send event to
...". If you open an event from file/attachment you get a prepopulated "add to
calender-form".

android.calendar.ics.adapter is a fork of https://f-droid.org/packages/org.dgtale.icsimport that uses the
ical4j library.

Required Android Permissions:

• READ_CALENDAR used to export events from calendar
• WRITE_EXTERNAL_STORAGE used to store the created ics-file so that it can be attached to email or send via bluetooth.