Minor tweaks to scripts so they work on older cmake versions or without cuda.

dlib/CMakeLists.txt

@@ -407,13 +407,10 @@ if (NOT TARGET dlib)
 
 
       if (DLIB_USE_CUDA)
-         find_package(CUDA)
+         find_package(CUDA 7.0)
 
-         if (CUDA_FOUND)
 
-            if (CUDA_VERSION_STRING LESS "7.0")
-               message(FATAL_ERROR "dlib requires CUDA version 7.0 or higher")
-            endif()
+         if (CUDA_FOUND)
 
             set(CUDA_HOST_COMPILATION_CPP ON)
             list(APPEND CUDA_NVCC_FLAGS "-arch=sm_30;-std=c++11")
@@ -506,6 +503,7 @@ if (NOT TARGET dlib)
 
    # Install the library
    if (NOT DLIB_IN_PROJECT_BUILD)
+       cmake_minimum_required(VERSION 2.8.8)
        if(UNIX)
            set_target_properties(dlib-shared PROPERTIES
                                         OUTPUT_NAME dlib 

dlib/use_cpp_11.cmake

@@ -25,7 +25,7 @@ if (CMAKE_VERSION VERSION_LESS "3.1")
          add_global_compiler_switch("-std=gnu++11")
          set(COMPILER_CAN_DO_CPP_11 1)
       elseif(GCC_VERSION VERSION_GREATER 4.3 OR GCC_VERSION VERSION_EQUAL 4.3)
-         message(WARNING "C++0x activated.")
+         message(STATUS "C++0x activated.")
          add_global_compiler_switch("-std=gnu++0x")
          set(COMPILER_CAN_DO_CPP_11 1)
       endif()