Add Play container

Play applications come packaged with the container code, so no
download is necessary. All that is required is to make detect the Play
application start script in detect, ensure this script is executable
in compile, and run the script with appropriate environment in
release.

[#51899933]
Merge 51899933-Play-container to master

[#51899933]
Fix path to start script

[#51899933]
Merge 51899933-Play-container to master

[#51899933]
Add Java to path

[#51899933]
Merge 51899933-Play-container to master

[#51899933]
Pass port directly to Play script

[#51899933]
Merge 51899933-Play-container to master

[Completes #51899933]
Pass Java options correctly

[#51899933]
Merge 51899933-Play-container to master

[#51899933]
Modify Java options passed to Play

Passing Java options to the Play startup script corrupts any with
embedded single quotes. Substitute escaped double quotes to avoid
this.

Also log the output of compile and detect for easier problem
diagnosis.

[#51899933]
Merge 51899933-Play-container to master

[#51899933]
Expunge XX:OnOutOfMemoryError option for Play

It seems that this option cannot be successfully passed to the Play
start script, so omit it.

[#51899933]
Merge 51899933-Play-container to master

[#51899933]
Improved OOM kill support

Passing

-XX:OnOutOfMemoryError='kill -9 %p'

to Java via the standard Play application start script cannot be done.

Bash ruins whatever combination of escapes are passed in and typically
java fails saying that the option -9 is invalid. See
http://stackoverflow.com/questions/5792049/xxonoutofmemoryerror-
kill-9-p-problem for general, if inconclusive, discussion of the
general problem.

To work around this problem, introduce a killjava script which
OpenJdk.compile places in the buildpack diagnostics directory.
Specify this script on -XX:OnOutOfMemoryError.

Also, improve test coverage.

[#51899933]
Merge 51899933-Play-container to master

[#51899933]
Avoid sanitising Java options for Play applications

This should no longer be necessary since the killjava script was
introduced.

[#51899933]
Merge 51899933-Play-container to master

[#51899933]
Change pkill switches to match Linux pkill

[#51899933]
Merge 51899933-Play-container to master

[#51899933]