Changes_HG

1.cudnn V5 support
 solution: (1)copy the cudnn.n from the latest caffe into this project. the new cudnn.h from the new caffe supports cudnn V5
           (2)replace cudnn_conv_layer.cu,cudnn_relu_layer.cu, cudnn_sigmoid_layer.cu, cudnn_tanh_layer.cu with their counterparts from the cudnn V5 supported official caffe codes. Please also replace their cudnn_*_layer.hpp as well.
           (3) delete "*_v3" in include/caffe/ex_layers/binary_conv_layer.hpp: e.g. change 'func_v3 ( param1, param2..)' to 'func (param1, param2, ..)' 

2.GCC version is too new in Ubuntu 16.04 causing "/usr/include/string.h:652:42: error: ‘memcpy’ was not declared in this scope"
solution: add a flag when compiling in CmakeLists.txt

before:
    if(UNIX OR APPLE)
       set(CMAKE_CXX_FLAGS "${CMAKE_CXX_FLAGS} -fPIC -Wall")
    endif()
after:
   if(UNIX OR APPLE)
       set(CMAKE_CXX_FLAGS "${CMAKE_CXX_FLAGS} -fPIC -Wall")
       set(CMAKE_CXX_FLAGS "${CMAKE_CXX_FLAGS} -D_FORCE_INLINES")
    endif()