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 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
Removing dead code from numpy test

Change-Id: Ia86aa2f3e49cccbc3c019d7a7e9fc8e72df748da
Incorporating changes from Slicer and improve style

Adding changes in Slicer's version of the file which have a include
guard and a sanity check for Swig_DIR.

Additionally renamed version variable to be prefixed with SWIG.

Added variable with define the SWIG version, and the hash in one place
to aid in all getting updated when a version changes.

Change-Id: I5bc26b2ec425f6e21e9822df08d28342352f6252
Moving dependency graph to end, to print all

Adding missing DEPENDENCIES variable to SimpleITK examples external
project.

Using Swig DEPENDENCIES variable in ExternalProject call.

Change-Id: Ic1a9913034354c48c80a34b4e7caad8c73018505
Extracting PCRE external project into separate file

Change-Id: Ib5cf08286bfc056709b004164261a0a7dfd4edbd
Remove unused FFT superbuild logic branch

Change-Id: I9a39b54d3b72d5a47fcf074e4a4d2e84a20820f8
Changing download URLS from SourceForge to Midas.

Change-Id: Ie5f26335e62591c0f9726bea32fa41f2507dcbeb
Rearrange CMakeLists for including C99 stdint

The installation paths needed to be earlier before the try compile so
that they could be used in the C99 sub-directory.

Change-Id: I4336e3a570193d1f76dcaa8e3f306a360c41b980
Importing C99 int header

These file have been obtained as revision r26 from:

  http://code.google.com/p/msinttypes

The files are licensed under BSD-like terms.

Change-Id: If3ce0654d45865efcd375b89b686e5528ad5a314
Include C99 directory when no stdint.h header it found.

These files also get installed into the SimpleITK directory when not
found.

Because this header file is not wrapped, and has the same name as the
system. It makes code cleaner to maintain the expected name. However,
it may cause conflict and incompatibilities if other project follow
the same pattern. The may be a rare occurrence and at the moment does
not appear worth the change.

Change-Id: I40c83cc09f07101a13c99735a5593fbbb39400cb
Merge topic 'SIMPLEITK-348_PythonThreading'

63dc1d3 Removing dead code from numpy test
932491e Merge branch 'SIMPLEITK-349_RemoveGitHashFromNighlties' into SIMPLEITK-348_PythonThreading
e9ce728 Enable Python threading by unlocking the GIL
Merge topic 'SIMPLEITK-350_Include_stdint_VS9'

7c5adf5 Include C99 directory when no stdint.h header it found.
394320b Importing C99 int header
d432f9c Rearrange CMakeLists for including C99 stdint
70616fa Adding missing quotes around @s, and numpy not required
21005ee BUG: missing dependency of dist.Python on actual python library
Merge topic 'SIMPLEITK-351_RefactorExternalSWIG'

8708bbb Changing download URLS from SourceForge to Midas.
2c6fb74 Remove unused FFT superbuild logic branch
538bcd1 Extracting PCRE external project into separate file
959f585 Moving dependency graph to end, to print all
95e092c Incorporating changes from Slicer and improve style