Shen 13 with jdk8 b98

1)b98 : changing code so as to work with jdk8 with lambda b98
2)Shen 13 : updating to Shen 13 sources. 
3)Updating readme mainly to point out that old versions of jdk 8 with lambda can be downloaded at http://download.java.net/lambda/b98/. Was unaware of this until yesterday.

Thanks to Greg Spurrier (https://github.com/gregspurrier) for pointing out the changes required  : https://groups.google.com/forum/#!msg/qilang/M5iFzoxx7QQ/eG98AWoI9v4J

http://www.shenlanguage.org/Documentation/shendoc.htm
http://download.java.net/lambda/b98/
http://download.java.net/lambda/b98/docs/api/
https://jdk8.java.net/lambda/