attempt to update to gcc-4.8 and fix user-config.jam

.travis.yml

@@ -25,17 +25,19 @@ addons:
   apt:
     sources:
     - boost-latest
+    - ppa:ubuntu-toolchain-r/test
     packages:
     - libboost1.55-all-dev
     - python2.7-dev
+    - g++-4.8
 
 before_install:
   - git submodule update --init --recursive
 
 install:
   - if [ $TRAVIS_OS_NAME == "osx" ]; then sudo brew install boost boost-build python27-dev; fi
-  - 'echo "using gcc : : ccache g++ -std=c++0x ;" > ~/user-config.jam'
-  - 'echo "using clang : : ccache clang++ -std=c++11 ;" >> ~/user-config.jam'
+  - 'echo "using gcc-4.8 : : ccache g++ : <cxxflags>-std=c++11 ;" > ~/user-config.jam'
+  - 'echo "using clang : : ccache clang++ : <cxxflags>-std=c++11 ;" >> ~/user-config.jam'
   - 'echo "using python : 2.7 ;" >> ~/user-config.jam'
   - ccache -V && ccache --show-stats && ccache --zero-stats
   - which $CXX