Added Eclipse project files for better EGit integration.
Improving logging performance

- Guard string concatenation by log level tests
- Send exceptions to the logger in place of syserr
Merge pull request #4 from jvermillard/loggerperf

Improved logging performance
Reorganisation of package code

 - moving cipher stuff in a cipher package
 - moving ByteArrayUtils to the util package
 - some log cleanup
 - added default tinydtls PSK to the hardcoded list (to be fixed next)
Merge pull request #6 from jvermillard/reorg-package

Reorganisation of package code
A storage abstraction for PSK

 - introduce a PskStorage interface which is a simple way to get psk
   for a given identity

 - a default in-memory implementation is provided for test/evaluation
   only, you need to be serious about the way you store your PSK and not
   keep them laying in your serer/client memoery

 - apply dependency inversion principle for pushing the user defined
   PSK storage to the inner handshakers

 - removed harcoded PSKs from Handshaker.java

 - updated examples to show how to provide your own keys using the
   PskStore
Merge pull request #7 from jvermillard/psk-store

A storage abstraction for PSK
Store PSK Identity in the DTLS Session

Once the DTLS session is started successfully the applicative level will
want to know the used identity.

So I'm storing it in the DTLS session
Merge pull request #8 from jvermillard/identity-in-dtls-session

Store PSK Identity in the DTLS Session
missing files for PR #7
Merge pull request #9 from jvermillard/missing-files

missing files for PR #7
added eclipse repository for finging element-connector jars

Signed-off-by: Julien Vermillard <jvermillard@sierrawireless.com>
Refactoring configuation and key management

The client and server handshaker class was loading keystore and
truststore. I removed this code, the store need to be given at
DTLSConnector creation.

It's removing clutter from the handshaker classes and help to understand
how/who/where the key are loaded (single responsability principle)

Removing setting in ScProperties

Removed default port:
In fact DTLS have no default port, this settign doesn't really make
sense.

Now you configure everything using the Java API of DTLSConnector
and DTLSConnectorConfiguration
removed integration tests

will provide them as a separate project
because it's pulling a lot of dependencies
Close session if the DTLS handshake fail

If an exception is raised during the handshake we close the session
so the client can retry the handshake later with the other credentials.

Also Fix #13 : closed sessions are not removed from the maps