Fixed const correctness issues in programs and tests
(cherry picked from commit e0225e4d7f18f4565224f4997af537533d06a80d)

Conflicts:
	programs/ssl/ssl_client2.c
	programs/ssl/ssl_server2.c
	programs/test/ssl_test.c
	programs/x509/cert_app.c
diff --git a/tests/suites/test_suite_rsa.function b/tests/suites/test_suite_rsa.function
index 398b3b3..72c2967 100644
--- a/tests/suites/test_suite_rsa.function
+++ b/tests/suites/test_suite_rsa.function
@@ -468,11 +468,11 @@
     rsa_context ctx;
     entropy_context entropy;
     ctr_drbg_context ctr_drbg;
-    char *pers = "test_suite_rsa";
+    const char *pers = "test_suite_rsa";
 
     entropy_init( &entropy );
     TEST_ASSERT( ctr_drbg_init( &ctr_drbg, entropy_func, &entropy,
-                                (unsigned char *) pers, strlen( pers ) ) == 0 );
+                                (const unsigned char *) pers, strlen( pers ) ) == 0 );
 
     rsa_init( &ctx, 0, 0 );