Thrift: Add "#include <cstdlib>" in a few places and s/malloc/std::malloc/

Summary:
There were a few places where we were calling malloc/reallaoc/free without
including cstdlib (or stdlib.h).  This is broken, but it worked because
other headers that we were including included stdlib.h.  However, on a
platform where this wasn't true, it broke the Thrift build.  This change
adds the proper includes.  It also changes malloc to std::malloc (same
with realloc and free) in a few places, because that is the correct way
of doing it when you include cstdlib.

Reviewed By: mcslee

Test Plan: Compiled Thrift.

Revert Plan: ok

Other Notes:
This bug was noticed by a Thrudb user, and the patch was sent in by
Ross McFarland.


git-svn-id: https://svn.apache.org/repos/asf/incubator/thrift/trunk@665487 13f79535-47bb-0310-9956-ffa450edef68
diff --git a/configure.ac b/configure.ac
index fd29a0f..a1b059f 100644
--- a/configure.ac
+++ b/configure.ac
@@ -56,6 +56,7 @@
 AC_CHECK_HEADERS([netinet/in.h])
 AC_CHECK_HEADERS([pthread.h])
 AC_CHECK_HEADERS([stddef.h])
+AC_CHECK_HEADERS([stdlib.h])
 AC_CHECK_HEADERS([sys/socket.h])
 AC_CHECK_HEADERS([sys/time.h])
 AC_CHECK_HEADERS([unistd.h])