[ITK-dev] Precompiled header support

[Matt McCormick]

Hi folks,

In the hope of reducing ITK build time, I started work on adding
pre-compiled header support to ITK here:

  http://review.source.kitware.com/#/c/20349/

Unfortunately, after testing the build times with both GCC and Clang,
there was no notable benefit to build times.  I'm abandoning the
patch, and hopefully the lesson is beneficial for any with false-hopes
of the advantages to pre-compiled headers!

Thanks,
Matt