add new server variables
Merge branch 'develop' into hannahg

Conflicts:
	demo/includes/sql/db_con.php
Merge branch 'develop' into hannahg
Merge branch 'develop' into hannahg
Merge branch 'develop' into hannahg
Merge branch 'mporam' into hannahg
Merge branch 'mporam' into hannahg
add sql query to json header from API in development environments
add error logging
add database connection error logging