DHE-PSK cipher suites
1. fixed the AES-CCM-16 suites
2. added DHE-PSK as a key-exchange algorithm type
3. Added infrastructure for new suites:
 * TLS_DHE_PSK_WITH_AES_128_GCM_SHA256
 * TLS_DHE_PSK_WITH_AES_256_GCM_SHA384
 * TLS_DHE_PSK_WITH_AES_128_CBC_SHA256
 * TLS_DHE_PSK_WITH_AES_256_CBC_SHA384
 * TLS_DHE_PSK_WITH_NULL_SHA256
 * TLS_DHE_PSK_WITH_NULL_SHA384
 * TLS_DHE_PSK_WITH_AES_128_CCM
 * TLS_DHE_PSK_WITH_AES_256_CCM
4. added test cases for new suites
5. set DHE parameters on test server when using PSK and a custom cipher
suite list
6. updated half premaster key size