Add ST_DelaunayTriangles.
Update the pom to use JDelaunay
Update the pom with the last JDelaunay version
Add two new functions to create delaunay and constrained delaunay triangulation.
Merge with master
Fix import
Fix Delaunay functions
Add jdelaunay dependency
Fix merge
Return geometryCollection instead of Geometry
Merge pull request #73 from ebocher/feature/tin_fcs

Add ST_Delaunay and ST_ConstrainedDelaunay

Two new functions have been added: `ST_Delaunay` and `ST_ConstrainedDelaunay`.

`ST_Delaunay` creates a Delaunay triangulation and returns a collection of
`Geometry`s. There are three possible signatures:
```mysql
SELECT ST_Delaunay(the_geom);
SELECT ST_Delaunay(the_geom, 0);
SELECT ST_Delaunay(the_geom, 1);
```

`ST_ConstrainedDelaunay` creates a constrained Delaunay triangulation and
returns a collection of `Geometry`s. Possible signatures:
```mysql
SELECT ST_ConstrainedDelaunay(the_geom);
SELECT ST_ConstrainedDelaunay(the_geom, 0);
SELECT ST_ConstrainedDelaunay(the_geom, 1);
```

The integer parameter is used to set the output format:

* 0 to return triangles as `MULTIPOLYGON`s
* 1 to return edges as `MULTILINESTRING`s

If none is specified, the default value is 0. I.e.,
```mysql
ST_ConstrainedDelaunay(the_geom) = ST_ConstrainedDelaunay(the_geom, 0)
```
are equivalent.

*Note*: If the z-value is equal to `NaN`, the algorithm sets a 0 value ordinate.

#### Comparison with PostGIS

```mysql
ST_DelaunayTriangles(geometry g1, float tolerance, int4 flags);
```
See http://postgis.org/documentation/manual-2.1SVN/ST_DelaunayTriangles.html

For the documentation:

## Examples

### `ST_Delaunay`
#### MULTIPOINT input, MULTIPOLYGON output
```mysql
SELECT ST_Delaunay('MULTIPOINT((0 0 1), (10 0 1), (10 10 1))'::Geometry);
```
Answer:    `MULTIPOLYGON(((0 0, 10 0, 10 10, 0 0)))`

```mysql
SELECT ST_Delaunay('MULTIPOINT((0 0 1), (10 0 1), (10 10 1), (5 5 1))'::Geometry);
```
Answer:    `MULTIPOLYGON(((0 0, 10 0, 5 5, 0 0)), ((10 0, 5 5, 10 10, 10 0)))`


#### MULTILINESTRING input, MULTIPOLYGON output
```mysql
SELECT ST_Delaunay('MULTILINESTRING((1.1 8 1, 8 8 1), (2 3.1 1, 8 5.1 1))'::Geometry);
```
Answer:    `MULTIPOLYGON(((1.1 8, 2 3.1, 8 5.1, 1.1 8)), ((1.1 8, 8 5.1, 8 8, 1.1 8)))`

#### POLYGON input, MULTIPOLYGON output
```mysql
SELECT ST_Delaunay('POLYGON((1.1 9 1, 1.1 3 1, 5.1 1.1 1, 9.5 6.4 1, 8.8 9.9 1, 5 8 1, 1.1 9 1))'::Geometry, 0);
```
Answer:    
```
MULTIPOLYGON(((1.1 9, 1.1 3, 5 8, 1.1 9)),
             ((1.1 9, 5 8, 8.8 9.9, 1.1 9)),
             ((8.8 9.9, 5 8, 9.5 6.4, 8.8 9.9)),
             ((5.1 1.1, 9.5 6.4, 5 8, 5.1 1.1)),
             ((5.1 1.1, 5 8, 1.1 3, 5.1 1.1)))
```

#### POLYGON input, MULTILINESTRING output
```mysql
SELECT ST_Delaunay('POLYGON((1.1 9 1, 1.1 3 1, 5.1 1.1 1, 9.5 6.4 1, 8.8 9.9 1, 5 8 1, 1.1 9 1))'::Geometry, 1);
```
Answer:
```
MULTILINESTRING((1.1 9, 1.1 3, 5 8, 1.1 9),
                (1.1 9, 5 8, 8.8 9.9, 1.1 9),
                (8.8 9.9, 5 8, 9.5 6.4, 8.8 9.9),
                (5.1 1.1, 9.5 6.4, 5 8, 5.1 1.1),
                (5.1 1.1, 5 8, 1.1 3, 5.1 1.1))
```

### `ST_ConstrainedDelaunay`
#### POLYGON input, MULTIPOLYGON output
```mysql
SELECT ST_ConstrainedDelaunay('POLYGON((1.9 8, 2.1 2.2, 7.1 2.2, 4.9 3.5, 7.5 8.1, 3.2 6, 1.9 8))'::Geometry);
```
Answer:
```
MULTIPOLYGON(((1.9 8, 2.1 2.2, 3.2 6, 1.9 8)),
             ((2.1 2.2, 3.2 6, 4.9 3.5, 2.1 2.2)),
             ((2.1 2.2, 4.9 3.5, 7.1 2.2, 2.1 2.2)),
             ((7.1 2.2, 4.9 3.5, 7.5 8.1, 7.1 2.2)),
             ((4.9 3.5, 3.2 6, 7.5 8.1, 4.9 3.5)),
             ((3.2 6, 1.9 8, 7.5 8.1, 3.2 6)))
```

#### POLYGON input, MULTILINESTRING output
```mysql
SELECT ST_ConstrainedDelaunay('MULTILINESTRING((2 7, 6 7),  (3.2 4.6, 5 9),(4.1 5, 6 5))'::Geometry, 1);
```
Answer:
```
MULTILINESTRING((2 7, 3.2 4.6),
                (3.2 4.6, 4.1 5),
                (4.1 5, 4.1818181818181825 7),
                (3.2 4.6, 4.1818181818181825 7),
                (2 7, 4.1818181818181825 7),
                (4.1818181818181825 7, 5 9),
                (2 7, 5 9),
                (3.2 4.6, 6 5),
                (4.1 5, 6 5),
                (4.1818181818181825 7, 6 5),
                (6 5, 6 7),
                (4.1818181818181825 7, 6 7),
                (5 9, 6 7))
```