* Remove duplications in rdpRsaKey, reuse rdpCertificate for public
components
* Move all private key and certificate code to certificate.c,
remove the tssk_* variables from gcc
* Handle update of client and server random keys in wrapping functions
* Simplify gcc_write_server_security_data, use certificate.c functions
to write the certificate data
* Refactor security_establish_keys, use the random values stored in
settings directly
CMake 2.8 does not support default visibility on windows.
To allow building tests add the FREERDP_LOCAL define for each
function that is internal to FreeRDP.
When build with testing these functions are exported and available
for use by tests.
