Adding GetPixelID method to image class.

This is the intended replacement for the GetPixelIDValue method as it
returns an enumerated type as opposed to an integer.

Updated PimpleImageBase to use PixelID enum where it can.

Change-Id: I13df278b4b0958411e3c2bb7b9ae1773e0c7c4f3
Updating tests to prefer GetPixelID

Change-Id: I2632780e15f3aed9b00a09c639de5ac7f07d1040
ImageSource filters now that PixelID enum for type.

Change-Id: I3a7e0222fbb922ecdf7f8cc95409febf247c7c9a
Internally prefer PixelIDValueEnum in ExecuteInternal method.

Change-Id: Ibd79df78d4dec203fb52af43290194f73d228551
Updating GetPixelIDValueAsString to additionally take enum.

Change-Id: I5f03a29cf3a8cbc31f81d184f470755f230a372f
fixup for testing changes

Change-Id: I8b95ba1676f0983114dce3d8f8b2fef8b2ddb599
Prefer PixelID enum in internal Execute method

Change-Id: I10e34da2adeb5a3b2c24b0661e2de46b20c5a039
Adding additional method to CastImageFilter for PixelID enum.

Update example to use preferred PixelID enum methods.

Change-Id: I7b6cac4e72b06c6557a19720eb67cd966f1ae34a
ignore overloaded PixelID methods where conflict occurs in SWIG.

For the wrapped languages where are not strongly typed the int and the
pseudo enum type are the same, causing a conflict for this overloaded
method. So, these languages ignore the int overloaded methods.

BUG: adding missing Ruby.i SWIG customization file

Change-Id: I95f1f851ba0849ef11a36bcb7e40a4401be76736
R now is requiring that enum be passed as strings

Updated tests to use pixel ID as strings.

This is not ideal, it would be better if there were variables with
predefined values which had the correct value to use as enums. this
would help with tab completion.

Change-Id: If3c9f939699649b8da06d048a0dcd2866879e460
BUG: Fixed ImageJ command line argument on Linux

Fixed a bug that was causing an annoying pop up in ImageJ whenever
the Show method was called on Linux systems.  Changed the image
file name was passed to ImageJ.  Now it is included in an open
command in the executed macro code.

Change-Id: Ic2902ccbec891d7050d22dbfab49026efd50e860
Enable Python threading by unlocking the GIL

Simply by passing the "-threads" flag to SWIG, the wrapping code will
now unlock the GIL during each C call. Currently, SimpleITK does not
have call back or event monitoring. Threading will make these features
more complicated.

Change-Id: Ia97913c1a9577a24e8d5cb481c4d9ec66ca32cc6
Merge topic 'SIMPLEITK-103_FixLinuxShow'

d0a3c41 BUG: Fixed ImageJ command line argument on Linux
Pass SimpleITK_* CMake variable from superbuild to external project

To remote the git hash from the nightly builds, the CMake variable
SimpleITK_BUILD_DISTRIBUTE needs to be defined in the actual SimpleITK
project. This is now accomplished introspectively examining and
passing all CMake variables which begin with SimpleITK_ from the
superbuild to the SimpleITK sub-project.

Change-Id: I1d83ab54797c05012155f74abb6bc7f025032e07
Tweak message for variables passed to ITK sub-project

Change-Id: I1e1c44dfe116a21e9794a2c166a6d667c819ab8c
Merge branch 'SIMPLEITK-349_RemoveGitHashFromNighlties' into SIMPLEITK-348_PythonThreading

Change-Id: Ib91127c89fa90e288421928371cdf68bfb71c990
BUG: missing dependency of dist.Python on actual python library

Because the same variable was for the SWIG target was used in both the
Python and R wrapper, a new alias variable needed to be created, which
include Python on the name.

Change-Id: I7f32e4a2b3dde0f04fc870027c6bd70c12cfb55a
Adding missing quotes around @s, and numpy not required

Having a space in the source name caused problems with the
installation due to unquoted @ substitutions.

If the python installation did not have numpy, a failing error would
be returned causing the build to appear to have failed. Now the
installation is just skip. So just a couple tests will fail.

Change-Id: Ia1bca43b0a642b0229f0079660e5be7292c3df6d
Pass Python build variables to ITK from superbuild

Change-Id: Ice2554e1c6917597a876542f7fc112ee00339aa6
Moved include of language options before ITK external

This should ensure the python variable are defined for ITK when
wrap ITK is enabled.

Change-Id: Iccafb2036ee85e1af81203cd8bd1c3cda790704f