[Building Sakai] Upgrade Pluto version to 1.1.7 for Sakai 2.8 - SAK-19011

[csev]

I just went through and figured out how to upgrade our Pluto version to 1.1.7 and tested Basic LTI as well as some other portlets and all  works well.   

A lot of stuff has been fixed between 1.1.2 and 1.1.7.  

http://portals.apache.org/pluto/v11/release-notes.html

Here is the JIRA for the change.

http://jira.sakaiproject.org/browse/SAK-19011

If anyone has any concern with this change, let me know.  I am planning to make the change to the /portal code and the master/pom.xml in a day or so unless someone has an issue.  The only dependency on the pluto version is in /portal - the portlets themselves only depend on the portlet jar.

/Chuck