AppDynamics Tier Name in Credentials

Previously, the tier name provided to the AppDynamics agent was hard-
coded in the component configuration file.  This meant that the only
way to change the tier name was to fork the buildpack; a heavy-weight
exercise.  This change makes the configured tier name, the "default"
choice which can be overridden with a 'tier-name' entry in the service
credentials.

[#75252498][#55][#59]
Merge branch 'cgfrost-75252498'

[resolves #81]
AppDynamics Node Name from Instance Index

Previously, AppDynamics node names were based on the instance's id.
This led to a proliferation of instances in the AppDynamics console
which hindered usability.  This change now uses the instance's index
for its node name.  This will lead to fewer instances in the
AppDynamics console, improving usability.

[#75252406][#55]
Merge branch 'cgfrost-75252406-AppDynamics-nodeName'

[resolves #83]
Update the AccessLog pattern to show more

The existing pattern doesn't show the IP address of the original requester.
This change adds a value of '%{org.apache.catalina.AccessLog.RemoteAddr}r' to
show the IP address of the original requester as provided by the RemoteIpValve.
'%a' will continue to show the IP address of the Router.

[#75588342]
Merge branch 'cgfrost-75588342-logging-pattern'

[resolves #75]
Update the Tomcat Access Log Pattern

Due to a change in the Access Logging produced by the GoRouter the
'X-Forwarded-For' header is no longer required. The commit removes it.

See: https://github.com/cloudfoundry/java-buildpack/issues/75#issuecomment-53535349

[#77701034]
Merge branch 'cgfrost-77701034-Access-Logs-Headers'

[resolves #75]
HTTPS Repository

Previously, the default repository root pointed at the HTTP endpoint
of download.run.pivotal.io.  This was due to the fact that the HTTPS
certificate (provided by CloudFront) did not match the URI.  The
CloudFront distribution has now been updated with a matching HTTPS
certificate, so this change updates the root to point at the HTTPS
endpoint.

[#77446526]
Merge 77446526-https to master

[#77446526]
Upgrade the default Java Version to 8

With the release of Java 8u20 it is time to move to Java 8. This commit changes
the default Java version that will be used by the Buildpack to '1.8.0_+'.

[#70715740]
Merge branch 'cgfrost-70715740-upgrade-to-java-8'
Update the Oracle JRE to Java 8

The Oracle JRE configuration needs to be updated to Java 8 to be consistent
with the Open JDK Java version. This commit changes that configuration.

[#70715740]
Merge branch 'cgfrost-70715740-upgrade-to-java-8'
Document usage of a proxy to access the network

The Java buildpack support deployments where a proxy is used to access
the Internet or local network but this is not documented. This commit
documents this support.

[#76620036]
Merge branch 'cgfrost-76620036-https-docs'
Expand the documentation around Spring profiles

This commit adds information about Spring profiles to the documentation for
auto-reconfiguration. It also expands the documentation about Spring profiles
for each of the relavent containers.

[#76772236]
Merge branch 'cgfrost-76772236-better-document-spring-profiles'

[resolves #86]
Packaging should handle missing platform versions

When packaging the Java buildpack it should just report that the requested
version for a specific platform can not be found and carry on. This commit makes
that change.

[#77005312]
Merge branch 'cgfrost-77005312-handle-missing-platform-versions'

[resolves #88]