Fix missing headers included by MQTTAsync.h

prevent segfault for unknown protocol in test app

Tweaks to ssl hostname verification

This patch updates the source code to not seg fault when an unknown
protocol is specified on the command line in the test app: paho_cs_sub

Previously the output would be:
```
./paho_cs_pub my/topic --host bad://test.mosquitto.org --port 8081
Using topic my/topic
Connecting
Segmentation fault (core dumped)
```

After this patch the output is:
```
./paho_cs_pub my/topic --host bad://test.mosquitto.org --port 8081
Using topic my/topic
Connecting
Failed to connect
```
Signed-off-by: Keith Holman <keith.holman@windriver.com>

Return SSL_FATAL, not SOCKET_ERROR so that connecting fails with a host we can't verify.
Also return an error for OpenSSL internal errors.
Free peername to avoid a memory leak.
Signed-off-by: Jasper Wallace <jasper@arcolaenergy.com>

fix memory out of bound access and stack overflow in UTF8_validate

Fix directory location mismatches

Fix typo in printf format string

Signed-off-by: Dominik Thalhammer <dominik@thalhammer.it>