Added Fancy Indexing for sparse matrix.
Fixed rebasing error.
Fixed rebasing error.
Added grad to GetItemList and its test.
Fixed GetItemList grad to support old scipy version.
Fixed GetItemList grad to support old scipy version.
Added GetItem2Lists function, its grad and all its tests.
Modified small mistakes in GetItemList and GetItem2Lists.
Made more change to GetItemList function.
Added csr_from_dense doc.
Merge pull request #1947 from Tanjay94/GetItemList

GetItemList