Added _monitoring schema to organize helper functions that report general database information. Moved 1 function to _monitoring schema, added three new monitoring functions.
	new file:   monitoring/fn_estimate_row_count.sql
	renamed:    utilities/fn_server_uptime.sql -> monitoring/fn_server_uptime.sql
	new file:   monitoring/fn_size_of_tables.sql
	new file:   utilities/fn_schema_exists.sql