COMP: CMake change that ensures ITK required modules are on.

SimpleITK assumes specific ITK modules are on, ensure this is the
case when using a system ITK, if it is not, issue a cmake error.

Change-Id: I9fdc9db93744d60fb3ed2a96e588bb636d3012be
Fixing conversion double to uint8_t conversion warning in test

This warning comes from gcc 4.1 on RHEL5.

Change-Id: I60621eb46196c3e5618ac29df5c0e3ffbc4b16ed
Merge branch 'SIMPLEITK-584_FixGCC4.1Warnings' into release

* SIMPLEITK-584_FixGCC4.1Warnings:
  Fixing conversion double to uint8_t conversion warning in test
Merge topic 'SIMPLEITK-586'

046f18ce COMP: CMake change that ensures ITK required modules are on.
Merge branch 'release'