1. Add a second select for tx.
2. Revised tcp_select to work for either rx or tx.
3. Updated client and server to use new tcp_select_tx() for checking the
tx socket if the nonblocking connect/accept would block on transmit.
1. In the client, check the return code on wolfSSL_CTX_SetMinDhKey_Sz() as it is checked in the server. (Resolves issue #2037.)
2. In HashOutput(), check that the hsHashes exists for the session before hashing. (Resolves issue #2038.)
* Added support for running as only Client (`-c`) or Server (`-s`).
* Added support for using sockets (in addition to in memory mode `-m`).
* Fixed support for 16KB test packet (memory version needed TLS header space). Changed to default to 16KB.
* Fixed so transfer is done on each connection and there is not transfer limit (instead "shutdown" message is used).
* Made pthread support optional and based on HAVE_PTHREAD.
* Tested non-blocking support with sockets or shared memory.
To use with localhost sockets and threading use `./examples/benchmark/tls_bench`
To use with threading and in-memory use `./examples/benchmark/tls_bench -m`
To use as separate server client applications with localhost sockets use: `./examples/benchmark/tls_bench -s` and `./examples/benchmark/tls_bench -c` in separate terminals.
```
./examples/benchmark/tls_bench -?
tls_bench 3.15.7 NOTE: All files relative to wolfSSL home dir
-? Help, print this usage
-c Run as client only, no threading and uses sockets
-s Run as server only, no threading and uses sockets
-h Host (default localhost)
-P Port (default 11112)
-e List Every cipher suite available
-i Show peer info
-l <str> Cipher suite list (: delimited)
-t <num> Time <num> (seconds) to run each test (default 1)
-p <num> The packet size <num> in bytes [1-16kB] (default 16384)
-v Show verbose output
-d Enable debug messages
-T <num> Number of threaded server/client pairs (default 1)
-m Use local memory, not socket
```
1. Fix testing issue with a client using the SCSV cipher suite to indicate desire for renegotiation.
2. Add indication to both the server and client examples that the renegotiation was successful.
1. Add the server side renegotiation flag to the secure renegotiation option.
2. Changed the AddEmptyNegotiationInfo so it doesn't create an extension, just adds a reply if SCR is enabled.
3. Fix the server's reaction to the client sending the SCR extension.
1. Add enables to the example server for turning on secure renegotiation.
2. Add encryption assists to the handhshake message handler functions.
3. Add a hello request message function. Includes handshake timing pre/postambles.
When loading DH domain parameters into a CTX, test the prime
immediately. When loading them into a session, test the prime right
before using it during the handshake. Sessions that get their prime from
their context do not need to test their prime. Added a function to
disable testing the prime in a session. The goal is to speed up testing
as every single test case loads DH parameters whether they are used or
not.
