Cholesky Decomposition - Modifications

* Removed ```getL```, ```getU``` and ```getD``` methods from ```CholeskyCommon``` and ```CholeskyLDU```.
* ```decompose``` methods in ```CholeskyCommon``` and ```CholeskyLDU``` return ```CholeskyResult```
* Removed ```setMaxEstimatedSize``` method from all classes in ```chol.impl``` package