Overridable media session pool size

git-svn-id: https://svn.pjsip.org/repos/pjproject/trunk@1448 74dad513-b988-da41-8d7b-12977e46ad98
diff --git a/pjmedia/src/pjmedia/session.c b/pjmedia/src/pjmedia/session.c
index ae72154..c2c4be9 100644
--- a/pjmedia/src/pjmedia/session.c
+++ b/pjmedia/src/pjmedia/session.c
@@ -39,8 +39,14 @@
 
 #define THIS_FILE		"session.c"
 
-#define PJMEDIA_SESSION_SIZE	(48*1024)
-#define PJMEDIA_SESSION_INC	1024
+#ifndef PJMEDIA_SESSION_SIZE
+#   define PJMEDIA_SESSION_SIZE	(10*1024)
+#endif
+
+#ifndef PJMEDIA_SESSION_INC
+#   define PJMEDIA_SESSION_INC	1024
+#endif
+
 
 static const pj_str_t ID_AUDIO = { "audio", 5};
 static const pj_str_t ID_VIDEO = { "video", 5};