COMP: Fix SSE2 build errors with WrapITK on GCC 4.9. (ForRelease)

As of gcc 4.9 the cmake test for emmintrin.h no longer depends on SSE2 support actually being enabled.
Gccxml has a problem with this since its parser is based on gcc-4.2.

See ITK-3299

Change-Id: I0dbd504e5202beae8f68930f3a21d2a348158b26
BUG: Improve SWIG version check

See ITK-3303
The swig version was checked before SWIG_VERSION was defined when using system swig.
There is now also a new variable, ITK_SWIG_VERSION, which defines ITK's swig version,
and is propagated to SWIG_VERSION when using ITK's swig.

Change-Id: Idc755567691d32543997797a7d85443a1488a3ed
Merge branch 'FixFitlerTypoForRelease' into release

Change-Id: Ibb05de6d27c6c94071d8b455b972d1eb7cc65ce3
Merge branch 'FixThresholdMaximumConnectedCompone' into release

Change-Id: I9104c6bad3f7fe319c3a644b120336912919a7b3
BUG: Add VTK_VERSION for older VTK versions

For older VTK's, VTK_VERSION is not defined. It needs to be setup manually.

See ITK-3304

Change-Id: I5efec656190e7417c7a2cbfa1b27b8b545261ca0
Merge branch 'release'

Change-Id: I2c4003bdb2f8ad7535a6ed3dd771b959f05e20a8
Merge topic 'FixSSE2'

409d8640 COMP: Fix SSE2 build errors with WrapITK on GCC 4.9. (ForRelease)