Base image for App Engine managed VM using Apache Tomcat 8.

Sample Dockerfile to add an application as the ROOT Context:

```Dockerfile
FROM appengine-tomcat
ADD . ROOT
```

This initial version simply sets up logging and ports for a simple application. Additional work
is required to support:

 * Session persistence with replication across servers.
 * Container-managed authentication.
 * Container-managed authorization.
 * API authorization using the system role account.
 * Sending JVM and Tomcat statistics to Google Cloud Monitoring (collectd).
 * Direct integration with Google Cloud Logging (fluentd).

Changes made to the default configuration:

 * Moved log files to /var/log/app_engine/custom_logs
 * Removed log configuration for manager and host-manager webapps.
 * Removed Listener entries for trapping memory leaks during redeployment.
 * Removed AJP Listener.
 * Use common Executor and raise maxThreads to 250
 * Single HTTP11 Connector
 * Removed UserRealm and local user database.
 * Added AppEngine request header valve.
 * Removed WatchedResource entries to disable webapp reloading.
 * Turn off "development" mode for JSPs.
 * Removed all default webapps and set WORKDIR to the webapps directory.

Base image for an App Engine custom runtime using Apache Tomcat 8.
This project is still in initial development and features may change at any time.
Please use the [issue tracker](https://github.com/GoogleCloudPlatform/appengine-container-tomcat/issues)
for feedback and suggestions.

To use this pre-release version you will need to build the container image yourself. Make sure
you have Apache Maven installed and Docker is running, then run:

```
$ mvn package docker:package
```

This will compile the support libraries and create a local Docker image tagged `appengine-tomcat`

To use this image and set your application as the ROOT Context, add the following Dockerfile
to the root of an exploded web application:

```Dockerfile
FROM appengine-tomcat
ADD . ROOT
```

This initial version simply sets up logging and ports for a simple application. Additional work
is required to support features such as:

 * Session persistence with replication across servers.
 * Container-managed authentication.
 * Container-managed authorization.
 * API authorization using the system role account.
 * Sending JVM and Tomcat statistics to Google Cloud Monitoring (collectd).
 * Direct integration with Google Cloud Logging (fluentd).

Please see the [issue tracker](https://github.com/GoogleCloudPlatform/appengine-container-tomcat/issues) for more details.

Changes made to the default configuration:

 * Moved log files to /var/log/app_engine/custom_logs
 * Removed log configuration for manager and host-manager webapps.
 * Removed Listener entries for trapping memory leaks during redeployment.
 * Removed AJP Listener.
 * Use common Executor and raise maxThreads to 250
 * Single HTTP11 Connector
 * Removed UserRealm and local user database.
 * Added AppEngine request header valve.
 * Removed WatchedResource entries to disable webapp reloading.
 * Turn off "development" mode for JSPs.
 * Removed all default webapps and set WORKDIR to the webapps directory.

Add more usage info to the readme
Add more usage info to the readme
