BUG: Eliminate unnecessary handling of version

Started to refactor and elminiate the unnecessary complex
handling of versions.  Previously the code required users
of BCD to ensure that the versions matched before model generation
and during all subsequent calls to the various landmark programs.

This hard codes the consistent versions in a single location so
that if future changes are necessary, only one string needs to be changed
to indicate a consistent set of files.
ENH: add the new template files to ReferenceAtlas/20141004_BCD directory

The current LLS model file (LLSModel_50Lmks.h5) and template model
file (T1_50Lmks.mdl) are updated.
New model files have version ID (version=2.0) embeded in them.
ENH: Remove wrong model files and update AutoWorkup scripts

The wrong model files directory (ReferenceAtlas/20140916_BCD) is
removed, since all corrected model files are placed in a new directory
called "ReferenceAtlas/20141004_BCD".
Also, AutoWorkup script is updated to have the new address of the model
files.
ENH: Update the BCD model files for internal TestSuite
ENH: Integration of ANTs Multimodal Registration into BRAINSFitHelper

While doing SyN registration, you can use SetFixedVolume2() and
SetMovingVolume2() in BRAINSFitHelper to run a multi modal image
registration.
In BRAINSFit, SyN registration had been hard coded to run one stage of
registration using ANTs.
Now this stage can have one or two metrics (for multi-modality
registration). All the parameters of the second metric is the same as
the first metric except for the fixed and moving volumes.
ENH: BRAINSABC multimodal functionality

Adding capabilities for the SyN stage of multi-modal registration in
BABC.  If there are more than 1 modality specified, then use
both modalities for the metric.