Use stock BouncyCastle, remove embedded libs, convert to Maven

.gitignore

@@ -1,4 +1,9 @@
 classes/
 doc/
 dist/
-
+.idea/
+.settings/
+*.iml
+.classpath
+.project
+target/

README.txt

@@ -26,33 +26,6 @@ the following hash and crypto algorithms:
 - AES
 - Diffie-Hellman (DH)
 
-The crypto part of the library was copied from BouncyCastle crypto library.
-Only the Diffie-Hellman part was modified to a new BigIntegerCrypto 
-implementation which is also part of this package. 
-
-BigIntegerCrypto re-uses the GNU BigInteger implementation and adds
-some crypto specific enhancements:
-
-- don't use the GMP library if installed on the system. While this
-  may reduce performance it gives us full control of the data (no
-  copying between Java and C)
-
-- Add a method to clear the contents / data of the big integer. The
-  application can use this function to clear data in case this big
-  integer was used as a private key. Some applications may stay in 
-  emory for a long time (for example communication applications) and
-  thus it is important to be able to clear secret data if it is not
-  longer used. Otherwise a malicious person could be able to do
-  memory analysis to find some key material.
-
-- Clear temporary data produced during calculations. Some big integer
-  calculation produce and use temporary data. BigIntegerCrypto clears
-  these temporary data to avoid data leakage. The tag "crypto:" 
-  identifies these modifications.
-
-Otherwise BigIntegerCrypto behaves in the same way as the normal
-BigInteger.
-
 The source distribution contains a short Java file that tests the 
 availability of the mentioned algorithms and support classes.