Fixed: Removed compiler warnings.

Last 3 are in NetMQ.zmq.PgmSender and are annotated for review.
Adding Secure Channel to netmq
Refactoring the DTLS over netmq
Checking the padding in the ValidateMac method.
Generating an IV from a counter instead from RandomNumberGenerator for better performance.
* add tests to secure channel

* add workflow validation to the handshake layer
* check the number of frames to make sure the message was not touched
Add documentation to the public methods and classes.
fix bug in the dispose methods
Added the proposed changes from reviewed Pullreq.

Compiles cleanly now.
Added NUnit console runner to execute UnitTests

This works even with the Visual Studio Express version.
Also tests can be debugged this way in VS Express.
Merge pull request #61 from tobi-tobsen/feature_NunitTestRunner

Added NUnit console runner to execute UnitTests
fixing a bug in the record layer , using BulkCipherAlgorithm.Null instead of null
Merge pull request #59 from somdoron/Security

Security
Replaced ReceiveAll and ReceiveAllString with ReceiveMessages and ReceiveStringMessages extension methods that use lazy loading, and marked existing methods as obsolete
Replaced usages of obsolete ReceiveAllString method with ReceiveStringMessages
Merge pull request #65 from almazik/master

Lazy implementation of receiving all messages
Merge pull request #56 from tobi-tobsen/refactoring_RemoveWarnings

Fixed: Removed compiler warnings
change the implementation of SocketBase.XRecv to return boolean instead of the message in order to not throw again exception.

Instead of throwning AgainException (which was thrown too much) only the Recv method throw the AgainException to the user, other internal methods return boolean indicate if the operation succeed.
change the implementation of the XSend as well. Now returning a boolean and return false instead of throwing Again Exception
Merge pull request #66 from somdoron/again_exception

Again exception fixes issue #57 too many exceptions
change the result variable to variable with meaningful name.