edit OrientDB license info so that GitHub recognizes it

GitHub uses a library called Licensee to identify a project's license
type. It shows this information in the status bar and via the API if it
can unambiguously identify the license.

This commit modifies a few of OrientDB's docs so that Licensee is able
to recognize the repository's license type.

Collectively, these changes allow Licensee to successfully identify the
license type of OrientDB as Apache 2.0.

Signed-off-by: Andrea Kao <eirinikos@gmail.com>

README.md

@@ -44,6 +44,26 @@ OrientDB Community Edition is free for any use (Apache 2 license). If you are in
 [Get started with OrientDB](http://orientdb.com/getting-started/).
 
 --------
+
+## Licensing
+OrientDB is licensed by OrientDB LTD under the Apache 2 license. OrientDB relies on the following 3rd party libraries, which are compatible with the Apache license:
+
+- Javamail: CDDL license (http://www.oracle.com/technetwork/java/faq-135477.html)
+- java persistence 2.0: CDDL license
+- JNA: Apache 2 (https://github.com/twall/jna/blob/master/LICENSE)
+- Hibernate JPA 2.0 API: Eclipse Distribution License 1.0
+- ASM: OW2
+
+References:
+- Apache 2 license (Apache2):
+  http://www.apache.org/licenses/LICENSE-2.0.html
+
+- Common Development and Distribution License (CDDL-1.0):
+  http://opensource.org/licenses/CDDL-1.0
+
+- Eclipse Distribution License (EDL-1.0):
+  http://www.eclipse.org/org/documents/edl-v10.php (http://www.eclipse.org/org/documents/edl-v10.php)
+
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