Add top-level release target - initial version

[ddebrunner]

Adds a 'release' target to the top-level build.xml that creates a tar bundle (in tmp) containing the toolkit and the sample toolkits.

The tar automatically includes the toolkit version and date of the build, note this does not yet include a build identifier in the version number. This is just groundwork for that step.

The bundle is intended for SPL developers that want to use the toolkit, not developers who want to modify the toolkit.

Pull request intended as an initial version, to get feedback on the contents etc.

[ddebrunner]

To be clear, I'm not saying this is a release or that the toolkit should make a release now, just working on the mechanisms to produce a release.

[ddebrunner]

This now includes pulling the hash into the the version number as the build identifier, when using the build from the top-level ant build.xml file.

It works by adding the token underscore-underscore-dev-underscore-underscore (avoiding markup!) as the build identifier in the info.xml and then when building from the top level substituting that with the commit hash obtained from git. After the build it unchecks out the info.xml. Thus this is intended only for a toplevel build against a clean codeline.

[hildrum]

Good stuff.

[ddebrunner]

Thanks, the top-level build.xml is mostly generic, so it has potential to be a common build.xml for all toolkits.