remove residual pthread references, but restore in build for gtest

gtest depends on pthread in Ubuntu 14.04

Makefile

@@ -158,7 +158,7 @@ ifneq ($(CPU_ONLY), 1)
 	LIBRARY_DIRS += $(CUDA_LIB_DIR)
 	LIBRARIES := cudart cublas curand
 endif
-LIBRARIES += \
+LIBRARIES += pthread \
 	glog gflags protobuf leveldb snappy \
 	lmdb \
 	boost_system \
@@ -277,7 +277,7 @@ LIBRARY_DIRS += $(BLAS_LIB)
 
 # Complete build flags.
 COMMON_FLAGS += $(foreach includedir,$(INCLUDE_DIRS),-I$(includedir))
-CXXFLAGS += -fPIC $(COMMON_FLAGS) $(WARNINGS)
+CXXFLAGS += -pthread -fPIC $(COMMON_FLAGS) $(WARNINGS)
 NVCCFLAGS := -ccbin=$(CXX) -Xcompiler -fPIC $(COMMON_FLAGS)
 # mex may invoke an older gcc that is too liberal with -Wuninitalized
 MATLAB_CXXFLAGS := $(CXXFLAGS) -Wno-uninitialized

include/caffe/loss_layers.hpp

@@ -8,7 +8,6 @@
 #include "boost/scoped_ptr.hpp"
 #include "hdf5.h"
 #include "leveldb/db.h"
-#include "pthread.h"
 
 #include "caffe/blob.hpp"
 #include "caffe/common.hpp"

include/caffe/neuron_layers.hpp

@@ -7,7 +7,6 @@
 
 #include "boost/scoped_ptr.hpp"
 #include "hdf5.h"
-#include "pthread.h"
 
 #include "caffe/blob.hpp"
 #include "caffe/common.hpp"

src/caffe/layers/data_layer.cpp

@@ -13,7 +13,7 @@
 
 namespace caffe {
 
-// This function is used to create a pthread that prefetches the data.
+// This function is used to create a thread that prefetches the data.
 template <typename Dtype>
 void DataLayer<Dtype>::InternalThreadEntry() {
   Datum datum;

src/caffe/layers/data_layer.cu

@@ -2,7 +2,6 @@
 #include <vector>
 
 #include "leveldb/db.h"
-#include "pthread.h"
 #include "stdint.h"
 
 #include "caffe/layer.hpp"

src/caffe/layers/image_data_layer.cpp

@@ -12,7 +12,7 @@
 
 namespace caffe {
 
-// This function is used to create a pthread that prefetches the data.
+// This function is used to create a thread that prefetches the data.
 template <typename Dtype>
 void ImageDataLayer<Dtype>::InternalThreadEntry() {
   Datum datum;

src/caffe/layers/window_data_layer.cpp

@@ -1,6 +1,3 @@
-//
-// Based on data_layer.cpp by Yangqing Jia.
-
 #include <stdint.h>
 
 #include <algorithm>

src/caffe/layers/window_data_layer.cu

@@ -1,7 +1,3 @@
-//
-// Based on data_layer.cpp by Yangqing Jia.
-
-#include <pthread.h>
 #include <stdint.h>
 
 #include <string>