ENH: Set cmake Minimums to 3.9.5

cmake version 3.9.5 provides support for C++11
in a forward compatible way.

Version 3.9.5 was choosen as it is the version of CMake that will be
available in Ubuntu's next long term release, 18.04.

  https://packages.ubuntu.com/bionic/cmake

Windows developers usually download the latest version from cmake.org
and macOS developers usually download the latest version from cmake.org
or use Homebrew, which is currently at 3.10.1: http://brewformulas.org/Cmake

Change-Id: I00d17f9b5ba010e5aa8f6dbe4a9259c2498bfb47

Author: hjmjohnson

CMakeLists.txt

@@ -1,13 +1,10 @@
-cmake_minimum_required(VERSION 2.8.12 FATAL_ERROR)
+cmake_minimum_required(VERSION 3.9.5 FATAL_ERROR)
 
 foreach(p
-    CMP0025 # CMake 3.0
-    CMP0028
-    CMP0042 # CMake 3.0
-    CMP0054 # CMake 3.1
-    CMP0056 # CMake 3.2
-    CMP0058 # CMake 3.3
-    CMP0063 # CMake 3.3.2
+    ## Only policies introduced after the cmake_minimum_required (3.8.2) need
+    ## to explicitly be set to NEW.
+    CMP0070 #3.10.0 Define ``file(GENERATE)`` behavior for relative paths.
+    CMP0071 #3.10.0 Let ``AUTOMOC`` and ``AUTOUIC`` process ``GENERATED`` files.
     )
   if(POLICY ${p})
     cmake_policy(SET ${p} NEW)