Allow Spring Insight to support multiple app instances

Spring Insight is a monitoring solution provided Pivotal[1].  It
monitors Spring web applications for performance and faults.  This
support is implemented as a framework that looks for a service called
'insight' and acts when it is found.  The framework downloads the
appropriate Insight agent from the Insight dashboard and configures it
so that it connects to the bound service properly.  Each instance of
an application is configured with the same name and Spring Insight can
not tell the difference between instances. This commit fixes this by
removing the application naming property supplied to Insight at
startup and adding a new plugin to the Insight agent that names
application activity from different instances based on instance name
set in the Cloudfoundry enviroment.

[1]: http://gopivotal.com/pivotal-products/apps/pivotal-tc-server

[62015878]
Merge 63747966-insight-improvements to master

[Completes #63747966]
After a DNS lookup failure, assume there is no internet connection.

This can occur in two places. If it occurs when sending a HEAD request
against a version of an item in the application cache, mark the
internet as unavailable and use the cached item. If it occurs when
downloading an item, mark the internet as unavailable and look for the
item in the buildpack cache.

[#66409480]
Merge 66409480-recover-from-dns-lookup-failure to 2.0.x

[Completes #66409480]