Update and add image of ST_CompactnessRatio
Update ST_CompactnessRatio
Update doc and image of ST_CompactnessRatio
Create doc of ST_Accum
Update and add image ST_Accum
Update image ST_Accum
Update ST_Accum
Create doc ST_SetSRID
Correction of ST_Accum
Correction ST_CompactnessRatio
Latest correction of ST_SetSRID
Update ST_accum
Update ST_SetSRID
Update ST_CompactnessRatio
Update link of ST_Explode in ST_Accum
Update link to ST_CompcatnessRatio
Update link of ST_SetSRID
Add link of ST_Accum
Improve explanation
Merge branch '138' into gh-pages

Update and add image of ST_CompactnessRatio