gcc 4.8 crashes while compiling embree. Disabling it for the linux build

Former-commit-id: e3c296f834ccdb2ee8b0591248468023cc1de515

.travis.yml

@@ -20,7 +20,7 @@ matrix:
         - cd tutorial
         - mkdir build
         - cd build
-        - cmake -DLIBIGL_USE_STATIC_LIBRARY=ON  -DCMAKE_CXX_COMPILER=g++-4.8 -DCMAKE_C_COMPILER=gcc-4.8 ../
+        - cmake -DLIBIGL_USE_STATIC_LIBRARY=ON  -DCMAKE_CXX_COMPILER=g++-4.8 -DCMAKE_C_COMPILER=gcc-4.8 -DLIBIGL_WITH_EMBREE=OFF ../
         - make -j 2
       addons:
         apt:

shared/cmake/CMakeLists.txt

@@ -1,6 +1,8 @@
 cmake_minimum_required(VERSION 2.8.12)
 project(libigl)
 
+message(DEPRECATION "shared/cmake/CMakeLists.txt is deprecated. Use libigl.cmake instead.")
+
 ### Available options ###
 option(LIBIGL_USE_STATIC_LIBRARY    "Use libigl as static library" OFF)
 option(LIBIGL_WITH_ANTTWEAKBAR      "Use AntTweakBar"    OFF)