Fixed inconsitent compiler requirements docs

Documentation/dev/build.md

@@ -41,9 +41,10 @@ Required:
     - Version 3.8 or newer, however, the latest version is always recommended
   * Supported compiler
     - GCC 4.8 or newer
-    - Clang 4 or newer
-    - Xcode 9 or newer
-    - Visual Studio 2015 or newer
+    - Clang 3.3 or newer
+    - Apple Clang 5.0 (from Xcode 5.0) or newer
+    - Microsoft Visual Studio 2015 or newer
+    - Intel 14.0 or newer
 
 Optional dependencies:
 

README.md

@@ -56,14 +56,16 @@ Requirements
 
 In general VTK tries to be as portable as possible; the specific configurations below are known to work and tested.
 
-VTK supports the following C++11 compilers:
-1. Microsoft Visual Studio 2015 or newer
-2. gcc 4.8.3 or newer
-3. Clang 3.3 or newer
-4. Apple Clang 5.0 (from Xcode 5.0) or newer
+VTK supports the following compilers:
+
+1. GCC 4.8 or newer
+2. Clang 3.3 or newer
+3. Apple Clang 5.0 (from Xcode 5.0) or newer
+4. Microsoft Visual Studio 2015 or newer
 5. Intel 14.0 or newer
 
 VTK supports the following operating systems:
+
 1. Windows Vista or newer
 2. Mac OS X 10.7 or newer
 3. Linux (ex: Ubuntu 12.04 or newer, Debian 4 or newer)