Merge 59473228-relative-paths to master

[Completes #59473228]
Avoid Groovy container detecting when there are .class files

Rather than code exceptions for specific files, such as
logback.groovy, ensure the Groovy container does not detect when there
are one or more .class files present.

[#61282032]
Avoid Spring Boot CLI container detecting shebang files with classes

[#61656448]
Merge 61282032-class-files-not-groovy to master

[Completes #61282032]
Separate Play 2.2.0+ applications

This change adds support for dist and staged Play 2.2 applications as
separate types.  This was non-obviously implemented previously, but
did not make the cut when the big refactoring happened last week.

[#59473228]
Merge 59473228-relative-paths to master

[Completes #59473228]
Helper behaviors

This change adds some helper behaviors that can be used by downstream
components.  Specifically, this adds the ability to execute a block
with JAVA_HOME set, and makes the copy_resources and download_jar
methods a bit more robust.
Add MariaDB JDBC framework

The MariaDB JDBC driver is used instead of the MySQL JDBC
driver since its license terms are more favourable.

[#52325391]
Merge 52325391-mariadb to master

[#52325391]
Add Postgresql JDBC framework

[#52325263]