Add googletest library and update makefiles

gtest/Makefile

@@ -0,0 +1,22 @@
+
+BUILD_DIR = ../build
+LIBS := -lpthread
+CPP_OBJS=$(BUILD_DIR)/gtest-all.o $(BUILD_DIR)/gtest-main.o
+
+SOURCES=gtest-all.cc gtest-main.cc
+
+
+# Each subdirectory must supply rules for building sources it contributes
+$(BUILD_DIR)/%.o: %.cc
+	@echo 'Building file: $<'
+	@echo 'Invoking: GCC C++ Compiler'
+	g++ -I../ -O0 -g3 -Wall -c -o"$@" "$<"
+	@echo 'Finished building: $<'
+	@echo ' '
+
+all: $(CPP_OBJS)
+
+clean:
+	-$(RM) $(CPP_OBJS) 
+	-@echo ' '
+