Add a few missing headers

Fixes build with gcc 4.3.2

Signed-off-by: Alexey Zaytsev <alexey.zaytsev@gmail.com>
diff --git a/tools/aidl/aidl.cpp b/tools/aidl/aidl.cpp
index 927d21e..dc61567 100644
--- a/tools/aidl/aidl.cpp
+++ b/tools/aidl/aidl.cpp
@@ -10,6 +10,8 @@
 #include <sys/stat.h>
 
 #include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
 #include <map>
 
 #ifdef HAVE_MS_C_RUNTIME
diff --git a/tools/aidl/generate_java.cpp b/tools/aidl/generate_java.cpp
index 7f84ff4..affac0f 100644
--- a/tools/aidl/generate_java.cpp
+++ b/tools/aidl/generate_java.cpp
@@ -1,6 +1,7 @@
 #include "generate_java.h"
 #include "AST.h"
 #include "Type.h"
+#include <string.h>
 #include <stdio.h>
 
 // =================================================
diff --git a/tools/aidl/options.h b/tools/aidl/options.h
index dc3c45a..e7e62ec 100644
--- a/tools/aidl/options.h
+++ b/tools/aidl/options.h
@@ -1,6 +1,7 @@
 #ifndef DEVICE_TOOLS_AIDL_H
 #define DEVICE_TOOLS_AIDL_H
 
+#include <string.h>
 #include <string>
 #include <vector>
 
diff --git a/tools/aidl/search_path.h b/tools/aidl/search_path.h
index 8d85d81..2bf94b1 100644
--- a/tools/aidl/search_path.h
+++ b/tools/aidl/search_path.h
@@ -5,6 +5,7 @@
 
 #if __cplusplus
 #include <vector>
+#include <string>
 using namespace std;
 extern "C" {
 #endif