* fixed the issue of including ghost cells in preconditioning, by zeroing out ghost rows and setting the diagonal to a large value.
* move altering of matrix to a function
* blockwise modification of matrix
* add findOverlapRowsAndColumns in BlacoilDetail. Add call to findOverlapRowsAndColumns in constructor of BlacoilModelEbos. Change makeOverlapRowsInvalid, by looping over precalculated inddies instead of grid
* Better formatting
andrthu