Create ~/.rnd with mode 0600 instead of 0666

Because of a missing include <fcntl.h> we don't have O_CREATE and don't create
the file with open() using mode 0600 but fall back to using fopen() with the
default umask followed by a chmod().

Problem found by Jakub Wilk <jwilk@debian.org>.
Link heartbeat_test with the static version of the libraries

It's using an internal API that that might not be available in the shared
library.
Update strength_bits for 3DES.

Fix strength_bits to 112 for 3DES.
SRP ciphersuite correction.

SRP ciphersuites do not have no authentication. They have authentication
based on SRP. Add new SRP authentication flag and cipher string.
Fix null pointer errors.

PR#3394
Create test/testutil.h for unit test helper macros

Defines SETUP_TEST_FIXTURE and EXECUTE_TEST, and updates ssl/heartbeat_test.c
using these macros. SETUP_TEST_FIXTURE makes use of the new TEST_CASE_NAME
macro, defined to use __func__ or __FUNCTION__ on platforms that support those
symbols, or to use the file name and line number otherwise. This should fix
several reported build problems related to lack of C99 support.