Added Fine Grained Saliency algorithm

Since now there is a saliency module, I would like to add an implementation of fine grained saliency, which fits nicely in the static section of the module.

Fine grained saliency is based on algorithms described in:
Montabone, Sebastian and Soto, Alvaro. "Human Detection Using a Mobile Platform and Novel Features Derived from a Visual Saliency Mechanism." Image and Vision Computing, 2010.

This pull request implements the staticSaliencyFineGrained class, so that a new saliency algorithm FINE_GRAINED is available. The code was originally released at http://www.samontab.com/web/saliency

 

You can see an example of it here:
![fgs_test](https://cloud.githubusercontent.com/assets/1005152/4875329/41ff361c-6292-11e4-9344-1175dbb49036.png)