Fix various memory leaks.
MPI types are now freed
freed cells in universe dictionary after its use in initialize
converted manual linked list for energy grid to linked list type from list header which allows it to be easily freed
Change list insert method to be compatible with get_item's last_elem pointer, and take advantage of sequential inserts
Set prev pointers in list_remove.
size method now used to determine the size of the linked list for unionized energy grid
analog fission tallies now tracked with fission logical due to new implicit fission model, updated test suite to reflect this
Merge branch 'develop' into clean
Merge pull request #207 from mit-crpg/clean

Fix Memory leaks from Valgrind
nu_fission not fission should be used when calculating expected nu total
updated results from change in nu
merged develop into test_suite
added no feedback and feedback CMFD tests
exclude cmfd cases when not compiling with PETSc
only process statepoint if run was successful