Summary of changes:
1. Always use the sxmo_notificationwrite.sh script to write notifications
rather then sometimes using echo to the DIR
2. Reorder args for notiffile spec to be action as 1st line, watchfile 2nd, and
rest as msg; this way msg can be multiple lines without propogating bugs
3. Write calls as a standard notification via sxmo_notificationwrite.sh
4. Use datestamps from notification files instead of filename, this way (3)
works without extra logic
5. Various style fixes
Note prefix stripping was unreliable because any +1XX number would break things.
The advice should be to always dial with +1 / international prefixes and store
contacts in your contacts.tsv with international codes; this way we avoid any
duplicate errors since we can be assured things in mmcli always come back w/
international prefixing automatically.