Buildbot: Remove CMake cache on all platforms

This way we are always sure that we are using latest ever configuration
without need to manually poke buildbot after doing changes in the building
environment.

Also uncomment code back, was a left-over from some debug.

build_files/buildbot/slave_compile.py

@@ -56,7 +56,6 @@ if 'cmake' in builder:
     chroot_name = None  # If not None command will be delegated to that chroot
     cuda_chroot_name = None  # If not None cuda compilationcommand will be delegated to that chroot
     build_cubins = True  # Whether to build Cycles CUDA kernels
-    remove_cache = False  # Remove CMake cache to be sure config is totally up-to-date
     remove_install_dir = False  # Remove installation folder before building
     bits = 64
 
@@ -71,7 +70,6 @@ if 'cmake' in builder:
     cuda_cmake_options = []
 
     if builder.startswith('mac'):
-        remove_cache = True
         install_dir = None
         # Set up OSX architecture
         if builder.endswith('x86_64_10_6_cmake'):
@@ -86,7 +84,6 @@ if 'cmake' in builder:
             cmake_options.append(['-G', '"Visual Studio 12 2013"'])
 
     elif builder.startswith('linux'):
-        remove_cache = True
         remove_install_dir = True
         cmake_config_file = "build_files/buildbot/config/blender_linux.cmake"
         cmake_player_config_file = "build_files/buildbot/config/blender_linux_player.cmake"
@@ -161,9 +158,9 @@ if 'cmake' in builder:
         # Configure the build
         print("CMake options:")
         print(target_cmake_options)
-#        if remove_cache and os.path.exists('CMakeCache.txt'):
-#            print("Removing CMake cache")
-#            os.remove('CMakeCache.txt')
+        if os.path.exists('CMakeCache.txt'):
+            print("Removing CMake cache")
+            os.remove('CMakeCache.txt')
         retcode = subprocess.call(target_chroot_prefix + ['cmake', blender_dir] + target_cmake_options)
         if retcode != 0:
             print('Condifuration FAILED!')