Open a connection to a database in UTF-8

Property definitions

sqlite3 $ NativeSqlite3 :: open
	# Open a connection to a database in UTF-8
	new open(filename: CString) `{
		sqlite3 *self = NULL;
		int err = sqlite3_open(filename, &self);
		nit_sqlite_open_error = err;
		return self;
	`}
lib/sqlite3/native_sqlite3.nit:140,2--146,3