Refactor reordering routines.

Move all the program reordering programs into their own file.
Also split the reordering routines for SPARSE_NORMAL_CHOLESKY
into individual library dependent routines.

Also get rid of RemovedFixedBlocksFromProgram.

Change-Id: Ie969f529e6d20dded9da021b9df1a040e08287c1
7 files changed