Update Java EE spec dependencies

This commit updates a number of dependencies upon Java EE specs to
use the preferred artifacts. Part of this change has been to move
to new API artifacts for both JSTL and JavaMail. In both cases these
new API jars are genuine API jars, i.e. they no longer contain an
implementation. Where needed, implementation dependencies have been
added.
Merge pull request #508 from wilkinsona/update-java-ee-dependencies

* update-java-ee-dependencies:
  Update Java EE spec dependencies