Eliminated NumberOfRoots ivar, cleaner implementation of initialization

Change-Id: Iac504211c41ce60fe9eef7e2d4bc6ad6022d6485
Implemented an IndexingMode iVar and convenience methods

Change-Id: I479a708b60328c802578541d4386a0776785a1c2
Implemented IJK/KJI indexing modes for hyper tree grid data set

Change-Id: Iba476de06c3c39ada4308a8960e10367296dede9
A new test for the IJK indexing

Change-Id: Ic26d7e908ffbf37206b7642707f36471dbc97d62
Modified HTG geometry filter to take care of IJK/KJI indexing

Change-Id: I271a9cf957a7909d5ded9b6de3339513a2b580c2
Fixed ShallowCopy defect

Change-Id: I68bfb91b87ec0708b9b11517fbfd758411a8b40a
Replaced the IndexingMode ivar with an TransposedRootIndexing bool

This is cleaner and makes more sense since there are only 2 modes
of indexing root cells: either IIK or KJI. It is not considered
that any other one would be potentially useful for anything.
So I am either transposing the default (i.e., VTK-style, that is
x-axis minor and z-axis major) to the x-axis major and z-axis
minor used by some applications.

Change-Id: Ic79f23622402c9579eefd57ea09743fb72788aa2
A new test to verify that transposed root indexing also works with materials

Change-Id: I402ac3c90f84fe5315fc8c6e0b242a72f4369e80
Merge topic 'add_kji_indexing_to_HTGrids' into master

59e0918f A new test to verify that transposed root indexing also works with materials
cc99b31b Replaced the IndexingMode ivar with an TransposedRootIndexing bool
12667426 Fixed ShallowCopy defect
e06b51f1 Modified HTG geometry filter to take care of IJK/KJI indexing
57313305 A new test for the IJK indexing
de9c7a8a Implemented IJK/KJI indexing modes for hyper tree grid data set
c3484110 Implemented an IndexingMode iVar and convenience methods
f49aaf78 Eliminated NumberOfRoots ivar, cleaner implementation of initialization