Remove $MEMORY_LIMIT disclaimer

Now that $MEMORY_LIMIT is available during staging, the disclaimer
about it is removed.

[#52785711]
Merge 52785711-memory-limit-docs to master

[Completes #52785711]
Add New Relic support

This change adds support for bound New Relic services.  The framework
notices a bound service in VCAP_SERVICES.  During the compile phase,
the New Relic agent JAR is download and a default New Relic
configuration file is copied into place.  During the release phase, a
number of JAVA_OPTS are configured such that the New Relic service is
used during the application's runtime.

[#53027669]