Updated group web page

[Sean Mullan]

Hi,

I have updated the OpenJDK Security Group web page [1] with a few changes:

- added more links to member blogs
- updated links from JDK 6 to JDK 7
- fixed broken link to Java Security book
- added macosx source packages
- and other small misc. changes

If you have any comments/feedback, please let us know.

Thanks,
Sean

[1] http://openjdk.java.net/groups/security/