JasyptPropertiesParser: Support for partially encrypted properties, custom encryptor

-Added support for decrypting parts of property values
-- Example property: some.endpoint=http://somehost?authUsername=username&authPassword=ENC(BjAoLxfpb1h)&token=ENC(ZWbB211g)
-- Decrypted result: some.endpoint=http://somehost?authUsername=username&authPassword=password&token=sometoken
-Added possibility to provide a custom encryptor (setEncryptor).
-- Useful when the encryptor is provided through an osgi service.

Note: The password and algorithm property is ignored when the encryptor property is set.
Test cases have been added in JasyptPropertiesParserTest.