STYLE: MersenneTwister move methods to cxx, docs

Change comments into doxygen strings, and clean up formatting
structure.

Move methods to cxx file that are not frequently used, that is just
for initialization.

Change-Id: I7d335b9dcc82a7d4a9da7a849d7bbdc9550ea700
ENH: Importing files from Noise Simulation Article

Importing files from "Noise Simulation" from the Insight Journal
http://hdl.handle.net/10380/3158

Change-Id: I05c8229ed7a9cef1a8311856de53af3f0027639a
STYLE: renaming files to standard ITK conventions

Change-Id: Ifc7b33cf9a0851806a4c53d474a16f58256cd731
ENH: Improving Noise Simulation Filters

Making KWStyle compliant via uncrustify.

Adding A Noise Base class for a common location to seed the noise.

Initializing random generators with common seed value, and threadId
into a simple hashing function.

Added common clamp function with rounding.

Change filters to not run in-place by default, as is standard and
expected behavior.

The noise parameters have been adjusted to produce ~20db peak signal
to noise. The output of the test is run through this calculator to
coarsely verify the results has the expected noise level.

Added const for numeric constants is computation loops.

Move PeakSignalToNoiseRationCalculator to testing directory, as it's
needed for testing but is not yet a proper ITK process object.

Switched to ScanlineIterators.

Change certain SmartPointers to C++ pointers in ThreadedGenerateData methods.

Change-Id: Icf5b3381cf1b13eb5288e3883322622002d8070e
Merge topic 'AddIJNoiseSimulation2'

723cad38 ENH: Improving Noise Simulation Filters
016fca8d STYLE: renaming files to standard ITK conventions
d637761d ENH: Importing files from Noise Simulation Article
ca30b42d STYLE: MersenneTwister move methods to cxx, docs