Add the ST_OrderingEquals specified in the SQL/MM specification: SQL-MM 3: 5.1.43
Merge pull request #269 from ebocher/validationFunctions

Add the ST_OrderingEquals 
as specified in the SQL/MM specification: SQL-MM 3: 5.1.43.

```mysql

SELECT ST_OrderingEquals(ST_GeomFromText('LINESTRING(0 0, 10 10)'),
		ST_GeomFromText('LINESTRING(0 0, 5 5, 10 10)'));
 st_orderingequals
-----------
 f
(1 row)

SELECT ST_OrderingEquals('LINESTRING(0 0, 10 10)'::GEOMETRY,
		'LINESTRING(0 0, 0 0, 10 10)'::GEOMETRY);
 st_orderingequals
-----------
 false
(1 row)

SELECT ST_OrderingEquals('LINESTRING(0 0, 10 10)'::GEOMETRY,
		'LINESTRING(0 0, 10 10)'::GEOMETRY);
 st_orderingequals
-----------
 true
(1 row)

SELECT ST_OrderingEquals('LINESTRING(0 0 1, 10 10 2)'::GEOMETRY,
		'LINESTRING(0 0 1, 10 10 2)'::GEOMETRY);
 st_orderingequals
-----------
 true
(1 row)

```