ENH: multi-process stream enhancements

This commit adds two main features to the
vtkMultiProcessStream object. First, it changes
the behavior of the Pop "array" methods. Now,
if the input array is not null, the code would expect
that the array is properly allocated, i.e., its size
should match the size of the data read and it would
just fill in the given buffer. Second, this commit adds
a method to get the size of the raw buffer that is returned
from calls to "GetRawData". The 1st byte of the raw buffer
is designated for the endianness, i.e., RawSize()=Size()+1.

Change-Id: Ic09fa0ca061548740fc72f57b4227495d7276035
ENH: Support for VtkIdType & enhancements

This method adds support for serializing/deserializing arrays
of vtkIdType. Further, it modifies the implementation such that
the array is popped from the bytestream directly in to the
pointer of the vtkDataArray instance as opposed to a temporary
buffer.

Change-Id: If090808933a5e4563d232b2657995c643536342f
ENH: NearlyEqual fuzzy comparator and SafeDivision

Added a "NearlyEqual" fuzzy comparator based on Knuth,
"The Art of Computer Programming (vol II)" and safe division
that catches overflow/underflow.

Change-Id: Iec61417c59936831a44f8961eeaa7d44c40bee64
ENH: Add vtkMPIUtilities -- parallel printf utils

Added vtkMPIUtilities which is intended to be used as
a centralized container to implement some common MPI
functions. Initially, vtkMPIUtilities provides support
for parallel printf

Change-Id: I8134636c13a0b960e66ae1ca7b89865a1cbc7a1a
ENH: Ghost zone generation for unstructured grids

This commit adds functionality for generating ghost zones
on a distributed unstructured grid.

Change-Id: Idd9ce355f8070bbdf882cdb2350fdcbce2c4b845
Merge topic 'unstructured-ghost-zones' into master

a07749d1 ENH: Ghost zone generation for unstructured grids
7c35e23a ENH: Add vtkMPIUtilities -- parallel printf utils
0f73b924 ENH: NearlyEqual fuzzy comparator and SafeDivision
55eb011a ENH: Support for VtkIdType & enhancements
01204dd4 ENH: multi-process stream enhancements