Fixed bug in SparseMatrix.Indices() for submatrix

When working with a sparse matrix submatrix the indices method returned
all the elements in the matrix. It should only return the elements in
the current submatrix. Now it does.

Signed-off-by: Tim Henderson <tim.tadh@gmail.com>
Bug-Fixed SparseMatrix.GetRowVector()

GetRowVector was not correctly returning a row vector. Now it is. There
should probably be some tests written for this as well.

Signed-off-by: Tim Henderson <tim.tadh@gmail.com>
Merge pull request #3 from timtadh/sparsefix

Sparsefix (Sparse Matrix Fixes)
Create LICENSE
Create AUTHORS
Update LICENSE
added ToLibSVM for SparseMatrix
merging sparse.go