Update issue notification

(cherry picked from commit 10b44226182fb21aa54056e0db5375fc555a54ed)
Specify path to installed schema

(cherry picked from commit 6007dfa2a1741e023af20210a460c3780a23b78f)

Conflicts:
	extension/Makefile.am
	extension/config.js.in
	extension/indicator.js
	extension/notifications.js
Enable extension on first run

(cherry picked from commit eaf4c2cc1e20c8cab7b67c124691994e88260a6e)

Conflicts:
	configure.ac
	lib/Makefile.am
Fix command line argument --preferences

(cherry picked from commit 8aaf1e1db2ea39e56a2ef0cb507a7e168189a6b2)
Suggest specifying --datadir for consistency

(cherry picked from commit 1f859f1da23cb3ac8aea45493ead027a4f072137)