License, Windows and Compatibility Upgrade (redux) (#19 )
* Replace GPL CRC with BSD CRC (zlib-ng/zlib-ng#42), for validation see https://github.com/neurolabusc/simd_crc

* Westmere detection

* Update configure for Westmere (InsightSoftwareConsortium/ITK#416)

* use cpu_has_pclmul() to autodetect CPU hardware (InsightSoftwareConsortium/ITK#416)

* remove gpl code

* Improve support for compiling using Windows (https://github.com/ningfei/zlib)

* Import ucm.cmake from https://github.com/ningfei/zlib

* crc32_simd as separate file (#18)

* atomic and SKIP_CPUID_CHECK (#18)

* Remove unused code

* Only allow compiler to use clmul instructions to crc_simd unit (jtkukunas/zlib#25)

* Atomic does not compile on Ubuntu 14.04

* Allow "cmake -DSKIP_CPUID_CHECK=ON .." to not check SIMD CRC support on execution.

* Restore Windows compilation using "nmake -f win32\Makefile.msc"

* zconf.h required for Windows nmake

* support crc intrinsics for ARM CPUs

* Requested changes (#19)